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1.  Meta-analysis of SHANK Mutations in Autism Spectrum Disorders: A Gradient of Severity in Cognitive Impairments 
PLoS Genetics  2014;10(9):e1004580.
SHANK genes code for scaffold proteins located at the post-synaptic density of glutamatergic synapses. In neurons, SHANK2 and SHANK3 have a positive effect on the induction and maturation of dendritic spines, whereas SHANK1 induces the enlargement of spine heads. Mutations in SHANK genes have been associated with autism spectrum disorders (ASD), but their prevalence and clinical relevance remain to be determined. Here, we performed a new screen and a meta-analysis of SHANK copy-number and coding-sequence variants in ASD. Copy-number variants were analyzed in 5,657 patients and 19,163 controls, coding-sequence variants were ascertained in 760 to 2,147 patients and 492 to 1,090 controls (depending on the gene), and, individuals carrying de novo or truncating SHANK mutations underwent an extensive clinical investigation. Copy-number variants and truncating mutations in SHANK genes were present in ∼1% of patients with ASD: mutations in SHANK1 were rare (0.04%) and present in males with normal IQ and autism; mutations in SHANK2 were present in 0.17% of patients with ASD and mild intellectual disability; mutations in SHANK3 were present in 0.69% of patients with ASD and up to 2.12% of the cases with moderate to profound intellectual disability. In summary, mutations of the SHANK genes were detected in the whole spectrum of autism with a gradient of severity in cognitive impairment. Given the rare frequency of SHANK1 and SHANK2 deleterious mutations, the clinical relevance of these genes remains to be ascertained. In contrast, the frequency and the penetrance of SHANK3 mutations in individuals with ASD and intellectual disability—more than 1 in 50—warrant its consideration for mutation screening in clinical practice.
Author Summary
Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders. Mutations altering genes involved in the junction between brain cells have been repeatedly associated in ASD. For example, SHANK1, SHANK2 and SHANK3 emerged as one family of genes that are associated with ASD. However, little was known about the number of patients carrying these mutations and the clinical outcome. Here, we performed a new genetic screen of SHANK mutations and these results were analyzed in combination with those of the literature. In summary, SHANK mutations account for ∼1% of patients with ASD and were detected in the whole spectrum of autism with a gradient of severity in cognitive impairment: mutations in SHANK1 were rare (0.04%) and present in males with normal IQ and autism; mutations in SHANK2 were present in 0.17% of patients with ASD and mild intellectual disability; mutations in SHANK3 were present in 0.69% of patients with ASD and up to 2.12% of the cases with moderate to profound intellectual disability. Given the high frequency and impact of SHANK3 mutations in individuals with ASD and intellectual disability—more than 1 in 50—this gene should be screened for mutations in clinical practice.
doi:10.1371/journal.pgen.1004580
PMCID: PMC4154644  PMID: 25188300
2.  Heterozygous FA2H mutations in autism spectrum disorders 
BMC Medical Genetics  2013;14:124.
Background
Widespread abnormalities in white matter development are frequently reported in cases of autism spectrum disorders (ASD) and could be involved in the disconnectivity suggested in these disorders. Homozygous mutations in the gene coding for fatty-acid 2-hydroxylase (FA2H), an enzyme involved in myelin synthesis, are associated with complex leukodystrophies, but little is known about the functional impact of heterozygous FA2H mutations. We hypothesized that rare deleterious heterozygous mutations of FA2H might constitute risk factors for ASD.
Methods
We searched deleterious mutations affecting FA2H, by genotyping 1256 independent patients with ASD genotyped using Genome Wide SNP arrays, and also by sequencing in independent set of 186 subjects with ASD and 353 controls. We then explored the impact of the identified mutations by measuring FA2H enzymatic activity and expression, in transfected COS7 cells.
Results
One heterozygous deletion within 16q22.3-q23.1 including FA2H was observed in two siblings who share symptoms of autism and severe cognitive impairment, axial T2-FLAIR weighted MRI posterior periventricular white matter lesions. Also, two rare non-synonymous mutations (R113W and R113Q) were reported. Although predictive models suggested that R113W should be a deleterious, we did not find that FA2H activity was affected by expression of the R113W mutation in cultured COS cells.
Conclusions
While our results do not support a major role for FA2H coding variants in ASD, a screening of other genes related to myelin synthesis would allow us to better understand the role of non-neuronal elements in ASD susceptibility.
doi:10.1186/1471-2350-14-124
PMCID: PMC4219428  PMID: 24299421
Autism; Brain; Gene; Myelin
3.  Characterization of SLITRK1 Variation in Obsessive-Compulsive Disorder 
PLoS ONE  2013;8(8):e70376.
Obsessive compulsive disorder (OCD) is a syndrome characterized by recurrent and intrusive thoughts and ritualistic behaviors or mental acts that a person feels compelled to perform. Twin studies, family studies, and segregation analyses provide compelling evidence that OCD has a strong genetic component. The SLITRK1 gene encodes a developmentally regulated stimulator of neurite outgrowth and previous studies have implicated rare variants in this gene in disorders in the OC spectrum, specifically Tourette syndrome (TS) and trichotillomania (TTM). The objective of the current study was to evaluate rare genetic variation in SLITRK1 in risk for OCD and to functionally characterize associated coding variants. We sequenced SLITRK1 coding exons in 381 individuals with OCD as well as in 356 control samples and identified three novel variants in seven individuals. We found that the combined mutation load in OCD relative to controls was significant (p = 0.036). We identified a missense N400I change in an individual with OCD, which was not found in more than 1000 control samples (P<0.05). In addition, we showed the the N400I variant failed to enhance neurite outgrowth in primary neuronal cultures, in contrast to wildtype SLITRK1, which enhanced neurite outgrowth in this assay. These important functional differences in the N400I variant, as compared to the wildtype SLITRK1 sequence, may contribute to OCD and OC spectrum symptoms. A synonymous L63L change identified in an individual with OCD and an additional missense change, T418S, was found in four individuals with OCD and in one individual without an OCD spectrum disorder. Examination of additional samples will help assess the role of rare SLITRK1 variation in OCD and in related psychiatric illness.
doi:10.1371/journal.pone.0070376
PMCID: PMC3749144  PMID: 23990902
4.  SHANK3 haploinsufficiency: a “common” but underdiagnosed highly penetrant monogenic cause of autism spectrum disorders 
Molecular Autism  2013;4:17.
Autism spectrum disorders (ASD) are etiologically heterogeneous, with hundreds of rare, highly penetrant mutations and genomic imbalances involved, each contributing to a very small fraction of cases. In this issue of Molecular Autism, Soorya and colleagues evaluated 32 patients with Phelan-McDermid syndrome, caused by either deletion of 22q13.33 or SHANK3 mutations, using gold-standard diagnostic assessments and showed that 84% met criteria for ASD, including 75% meeting criteria for autism. This study and prior studies demonstrate that this syndrome appears to be one of the more penetrant causes of ASD. In this companion review, we show that in samples ascertained for ASD, SHANK3 haploinsufficiency is one of the more prevalent monogenic causes of ASD, explaining at least 0.5% of cases. We note that SHANK3 haploinsufficiency remains underdiagnosed in ASD and developmental delay, although with the increasingly widespread use of chromosomal microarray analysis and targeted sequencing of SHANK3, the number of cases is bound to rise.
doi:10.1186/2040-2392-4-17
PMCID: PMC3695795  PMID: 23758743
5.  Prospective investigation of autism and genotype-phenotype correlations in 22q13 deletion syndrome and SHANK3 deficiency 
Molecular Autism  2013;4:18.
Background
22q13 deletion syndrome, also known as Phelan-McDermid syndrome, is a neurodevelopmental disorder characterized by intellectual disability, hypotonia, delayed or absent speech, and autistic features. SHANK3 has been identified as the critical gene in the neurological and behavioral aspects of this syndrome. The phenotype of SHANK3 deficiency has been described primarily from case studies, with limited evaluation of behavioral and cognitive deficits. The present study used a prospective design and inter-disciplinary clinical evaluations to assess patients with SHANK3 deficiency, with the goal of providing a comprehensive picture of the medical and behavioral profile of the syndrome.
Methods
A serially ascertained sample of patients with SHANK3 deficiency (n = 32) was evaluated by a team of child psychiatrists, neurologists, clinical geneticists, molecular geneticists and psychologists. Patients were evaluated for autism spectrum disorder using the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule-G.
Results
Thirty participants with 22q13.3 deletions ranging in size from 101 kb to 8.45 Mb and two participants with de novo SHANK3 mutations were included. The sample was characterized by high rates of autism spectrum disorder: 27 (84%) met criteria for autism spectrum disorder and 24 (75%) for autistic disorder. Most patients (77%) exhibited severe to profound intellectual disability and only five (19%) used some words spontaneously to communicate. Dysmorphic features, hypotonia, gait disturbance, recurring upper respiratory tract infections, gastroesophageal reflux and seizures were also common. Analysis of genotype-phenotype correlations indicated that larger deletions were associated with increased levels of dysmorphic features, medical comorbidities and social communication impairments related to autism. Analyses of individuals with small deletions or point mutations identified features related to SHANK3 haploinsufficiency, including ASD, seizures and abnormal EEG, hypotonia, sleep disturbances, abnormal brain MRI, gastroesophageal reflux, and certain dysmorphic features.
Conclusions
This study supports findings from previous research on the severity of intellectual, motor, and speech impairments seen in SHANK3 deficiency, and highlights the prominence of autism spectrum disorder in the syndrome. Limitations of existing evaluation tools are discussed, along with the need for natural history studies to inform clinical monitoring and treatment development in SHANK3 deficiency.
doi:10.1186/2040-2392-4-18
PMCID: PMC3707861  PMID: 23758760
22q13 deletion syndrome; Autism; Microarrays; Mutation; Phelan-McDermid syndrome; SHANK3
6.  Network Topologies and Convergent Aetiologies Arising from Deletions and Duplications Observed in Individuals with Autism 
PLoS Genetics  2013;9(6):e1003523.
Autism Spectrum Disorders (ASD) are highly heritable and characterised by impairments in social interaction and communication, and restricted and repetitive behaviours. Considering four sets of de novo copy number variants (CNVs) identified in 181 individuals with autism and exploiting mouse functional genomics and known protein-protein interactions, we identified a large and significantly interconnected interaction network. This network contains 187 genes affected by CNVs drawn from 45% of the patients we considered and 22 genes previously implicated in ASD, of which 192 form a single interconnected cluster. On average, those patients with copy number changed genes from this network possess changes in 3 network genes, suggesting that epistasis mediated through the network is extensive. Correspondingly, genes that are highly connected within the network, and thus whose copy number change is predicted by the network to be more phenotypically consequential, are significantly enriched among patients that possess only a single ASD-associated network copy number changed gene (p = 0.002). Strikingly, deleted or disrupted genes from the network are significantly enriched in GO-annotated positive regulators (2.3-fold enrichment, corrected p = 2×10−5), whereas duplicated genes are significantly enriched in GO-annotated negative regulators (2.2-fold enrichment, corrected p = 0.005). The direction of copy change is highly informative in the context of the network, providing the means through which perturbations arising from distinct deletions or duplications can yield a common outcome. These findings reveal an extensive ASD-associated molecular network, whose topology indicates ASD-relevant mutational deleteriousness and that mechanistically details how convergent aetiologies can result extensively from CNVs affecting pathways causally implicated in ASD.
Author Summary
Autism Spectrum Disorders (ASD) are characterised by impairments in social interaction and communication, and restricted and repetitive behaviours. ASD are highly heritable and many different stretches of DNA have been found to be duplicated or deleted in individuals with ASD. We found that an unusually high number of genes affected by these DNA deletions/duplications are associated with the functioning of synaptic transmission between nerve cells. The proteins made by many of these genes are known to interact with each other and, together with proteins from other deleted/duplicated genes, form a large interlinked biological network. This network was affected by almost 50% of the deletions/duplications in the ASD patients considered. Many individual ASD patients had deletions or duplications of multiple genes within this network, but for those patients with just a single gene from the network changed, that single gene appeared to play an important role. Furthermore, the network predicts that the effects arising from the genes in the deletions are similar to the effects arising from the genes in the duplications. Thus, the way that this ASD-associated network is wired together contributes to the understanding of the impact of these DNA deletions and duplications.
doi:10.1371/journal.pgen.1003523
PMCID: PMC3675007  PMID: 23754953
7.  Network- and Attribute-Based Classifiers Can Prioritize Genes and Pathways for Autism Spectrum Disorders and for Intellectual Disability 
Autism spectrum disorders (ASD) are a group of related neurodevelopmental disorders with significant combined prevalence (~1%) and high heritability. Dozens of individually rare genes and loci associated with high-risk for ASD have been identified, which overlap extensively with genes for intellectual disability (ID). However, studies indicate that there may be hundreds of genes that remain to be identified. The advent of inexpensive massively parallel nucleotide sequencing can reveal the genetic underpinnings of heritable complex diseases, including ASD and ID. However, whole exome sequencing (WES) and whole genome sequencing (WGS) provides an embarrassment of riches, where many candidate variants emerge. It has been argued that genetic variation for ASD and ID will cluster in genes involved in distinct pathways and protein complexes. For this reason, computational methods that prioritize candidate genes based on additional functional information such as protein-protein interactions or association with specific canonical or empirical pathways, or other attributes, can be useful. In this study we applied several supervised learning approaches to prioritize ASD or ID disease gene candidates based on curated lists of known ASD and ID disease genes. We implemented two network-based classifiers and one attribute-based classifier to show that we can rank and classify known, and predict new, genes for these neurodevelopmental disorders. We also show that ID and ASD share common pathways that perturb an overlapping synaptic regulatory subnetwork. We also show that features relating to neuronal phenotypes in mouse knockouts can help in classifying neurodevelopmental genes. Our methods can be applied broadly to other diseases helping in prioritizing newly identified genetic variation that emerge from disease gene discovery based on WES and WGS.
doi:10.1002/ajmg.c.31330
PMCID: PMC3505691  PMID: 22499558
High-throughput sequencing; massively parallel sequencing; gene discovery; networks; pathways; neurodevelopmental disorders; classifiers; support vector machine
9.  Autism multiplex family with 16p11.2p12.2 microduplication syndrome in monozygotic twins and distal 16p11.2 deletion in their brother 
The pericentromeric region of chromosome 16p is rich in segmental duplications that predispose to rearrangements through non-allelic homologous recombination. Several recurrent copy number variations have been described recently in chromosome 16p. 16p11.2 rearrangements (29.5–30.1 Mb) are associated with autism, intellectual disability (ID) and other neurodevelopmental disorders. Another recognizable but less common microdeletion syndrome in 16p11.2p12.2 (21.4 to 28.5–30.1 Mb) has been described in six individuals with ID, whereas apparently reciprocal duplications, studied by standard cytogenetic and fluorescence in situ hybridization techniques, have been reported in three patients with autism spectrum disorders. Here, we report a multiplex family with three boys affected with autism, including two monozygotic twins carrying a de novo 16p11.2p12.2 duplication of 8.95 Mb (21.28–30.23 Mb) characterized by single-nucleotide polymorphism array, encompassing both the 16p11.2 and 16p11.2p12.2 regions. The twins exhibited autism, severe ID, and dysmorphic features, including a triangular face, deep-set eyes, large and prominent nasal bridge, and tall, slender build. The eldest brother presented with autism, mild ID, early-onset obesity and normal craniofacial features, and carried a smaller, overlapping 16p11.2 microdeletion of 847 kb (28.40–29.25 Mb), inherited from his apparently healthy father. Recurrent deletions in this region encompassing the SH2B1 gene were recently reported in early-onset obesity and in individuals with neurodevelopmental disorders associated with phenotypic variability. We discuss the clinical and genetic implications of two different 16p chromosomal rearrangements in this family, and suggest that the 16p11.2 deletion in the father predisposed to the formation of the duplication in his twin children.
doi:10.1038/ejhg.2011.244
PMCID: PMC3330222  PMID: 22234155
duplication 16p11.2p12.2; deletion 16p11.2; autism; intellectual disability; SH2B1; SNP array
10.  Patterns and rates of exonic de novo mutations in autism spectrum disorders 
Nature  2012;485(7397):242-245.
Autism spectrum disorders (ASD) are believed to have genetic and environmental origins, yet in only a modest fraction of individuals can specific causes be identified1,2. To identify further genetic risk factors, we assess the role of de novo mutations in ASD by sequencing the exomes of ASD cases and their parents (n= 175 trios). Fewer than half of the cases (46.3%) carry a missense or nonsense de novo variant and the overall rate of mutation is only modestly higher than the expected rate. In contrast, there is significantly enriched connectivity among the proteins encoded by genes harboring de novo missense or nonsense mutations, and excess connectivity to prior ASD genes of major effect, suggesting a subset of observed events are relevant to ASD risk. The small increase in rate of de novo events, when taken together with the connections among the proteins themselves and to ASD, are consistent with an important but limited role for de novo point mutations, similar to that documented for de novo copy number variants. Genetic models incorporating these data suggest that the majority of observed de novo events are unconnected to ASD, those that do confer risk are distributed across many genes and are incompletely penetrant (i.e., not necessarily causal). Our results support polygenic models in which spontaneous coding mutations in any of a large number of genes increases risk by 5 to 20-fold. Despite the challenge posed by such models, results from de novo events and a large parallel case-control study provide strong evidence in favor of CHD8 and KATNAL2 as genuine autism risk factors.
doi:10.1038/nature11011
PMCID: PMC3613847  PMID: 22495311
11.  Autism multiplex family with 16p11.2p12.2 microduplication syndrome in monozygotic twins and distal 16p11.2 deletion in their brother 
The pericentromeric region of chromosome 16p is rich in segmental duplications that predispose to rearrangements through non-allelic homologous recombination. Several recurrent copy number variations have been described recently in chromosome 16p. 16p11.2 rearrangements (29.5–30.1 Mb) are associated with autism, intellectual disability and other neurodevelopmental disorders. Another recognizable but less common microdeletion syndrome in 16p11.2p12.2 (21.4 to 28.5–30.1 Mb) has been described in six individuals with intellectual disability, while apparently reciprocal duplications, studied by standard cytogenetic and FISH techniques, have been reported in three patients with autism spectrum disorders. Here we report a multiplex family with three boys affected with autism, including two monozygotic twins carrying a de novo 16p11.2p12.2 duplication of 8.95 Mb (21.28–30.23 Mb) characterized by SNP array, encompassing both the 16p11.2 and 16p11.2p12.2 regions. The twins exhibited autism, severe intellectual disability, and dysmorphic features, including a triangular face, deep-set eyes, large and prominent nasal bridge, and tall, slender build. The eldest brother presented with autism, mild intellectual disability, early onset obesity and normal craniofacial features, and carried a smaller, overlapping 16p11.2 microdeletion of 847 kb (28.40–29.25 Mb), inherited from his apparently healthy father. Recurrent deletions in this region encompassing the SH2B1 gene were recently reported in early onset obesity and in individuals with neurodevelopmental disorders, associated with phenotypic variability. We discuss the clinical and genetic implications of two different 16p chromosomal rearrangements in this family, and suggest that the 16p11.2 deletion in the father predisposed to the formation of the duplication in his twin children.
doi:10.1038/ejhg.2011.244
PMCID: PMC3330222  PMID: 22234155
Abnormalities, Multiple; genetics; Adolescent; Adult; Autistic Disorder; genetics; Chromosomes, Human, Pair 16; genetics; DNA Copy Number Variations; Gene Duplication; Humans; Male; Phenotype; Sequence Deletion; Siblings; Twins, Monozygotic; genetics; duplication 16p11.2p12.2; deletion 16p11.2; autism; intellectual disability; SH2B1; SNP array
12.  Individual common variants exert weak effects on the risk for autism spectrum disorderspi 
Anney, Richard | Klei, Lambertus | Pinto, Dalila | Almeida, Joana | Bacchelli, Elena | Baird, Gillian | Bolshakova, Nadia | Bölte, Sven | Bolton, Patrick F. | Bourgeron, Thomas | Brennan, Sean | Brian, Jessica | Casey, Jillian | Conroy, Judith | Correia, Catarina | Corsello, Christina | Crawford, Emily L. | de Jonge, Maretha | Delorme, Richard | Duketis, Eftichia | Duque, Frederico | Estes, Annette | Farrar, Penny | Fernandez, Bridget A. | Folstein, Susan E. | Fombonne, Eric | Gilbert, John | Gillberg, Christopher | Glessner, Joseph T. | Green, Andrew | Green, Jonathan | Guter, Stephen J. | Heron, Elizabeth A. | Holt, Richard | Howe, Jennifer L. | Hughes, Gillian | Hus, Vanessa | Igliozzi, Roberta | Jacob, Suma | Kenny, Graham P. | Kim, Cecilia | Kolevzon, Alexander | Kustanovich, Vlad | Lajonchere, Clara M. | Lamb, Janine A. | Law-Smith, Miriam | Leboyer, Marion | Le Couteur, Ann | Leventhal, Bennett L. | Liu, Xiao-Qing | Lombard, Frances | Lord, Catherine | Lotspeich, Linda | Lund, Sabata C. | Magalhaes, Tiago R. | Mantoulan, Carine | McDougle, Christopher J. | Melhem, Nadine M. | Merikangas, Alison | Minshew, Nancy J. | Mirza, Ghazala K. | Munson, Jeff | Noakes, Carolyn | Nygren, Gudrun | Papanikolaou, Katerina | Pagnamenta, Alistair T. | Parrini, Barbara | Paton, Tara | Pickles, Andrew | Posey, David J. | Poustka, Fritz | Ragoussis, Jiannis | Regan, Regina | Roberts, Wendy | Roeder, Kathryn | Roge, Bernadette | Rutter, Michael L. | Schlitt, Sabine | Shah, Naisha | Sheffield, Val C. | Soorya, Latha | Sousa, Inês | Stoppioni, Vera | Sykes, Nuala | Tancredi, Raffaella | Thompson, Ann P. | Thomson, Susanne | Tryfon, Ana | Tsiantis, John | Van Engeland, Herman | Vincent, John B. | Volkmar, Fred | Vorstman, JAS | Wallace, Simon | Wing, Kirsty | Wittemeyer, Kerstin | Wood, Shawn | Zurawiecki, Danielle | Zwaigenbaum, Lonnie | Bailey, Anthony J. | Battaglia, Agatino | Cantor, Rita M. | Coon, Hilary | Cuccaro, Michael L. | Dawson, Geraldine | Ennis, Sean | Freitag, Christine M. | Geschwind, Daniel H. | Haines, Jonathan L. | Klauck, Sabine M. | McMahon, William M. | Maestrini, Elena | Miller, Judith | Monaco, Anthony P. | Nelson, Stanley F. | Nurnberger, John I. | Oliveira, Guiomar | Parr, Jeremy R. | Pericak-Vance, Margaret A. | Piven, Joseph | Schellenberg, Gerard D. | Scherer, Stephen W. | Vicente, Astrid M. | Wassink, Thomas H. | Wijsman, Ellen M. | Betancur, Catalina | Buxbaum, Joseph D. | Cook, Edwin H. | Gallagher, Louise | Gill, Michael | Hallmayer, Joachim | Paterson, Andrew D. | Sutcliffe, James S. | Szatmari, Peter | Vieland, Veronica J. | Hakonarson, Hakon | Devlin, Bernie
Human Molecular Genetics  2012;21(21):4781-4792.
While it is apparent that rare variation can play an important role in the genetic architecture of autism spectrum disorders (ASDs), the contribution of common variation to the risk of developing ASD is less clear. To produce a more comprehensive picture, we report Stage 2 of the Autism Genome Project genome-wide association study, adding 1301 ASD families and bringing the total to 2705 families analysed (Stages 1 and 2). In addition to evaluating the association of individual single nucleotide polymorphisms (SNPs), we also sought evidence that common variants, en masse, might affect the risk. Despite genotyping over a million SNPs covering the genome, no single SNP shows significant association with ASD or selected phenotypes at a genome-wide level. The SNP that achieves the smallest P-value from secondary analyses is rs1718101. It falls in CNTNAP2, a gene previously implicated in susceptibility for ASD. This SNP also shows modest association with age of word/phrase acquisition in ASD subjects, of interest because features of language development are also associated with other variation in CNTNAP2. In contrast, allele scores derived from the transmission of common alleles to Stage 1 cases significantly predict case status in the independent Stage 2 sample. Despite being significant, the variance explained by these allele scores was small (Vm< 1%). Based on results from individual SNPs and their en masse effect on risk, as inferred from the allele score results, it is reasonable to conclude that common variants affect the risk for ASD but their individual effects are modest.
doi:10.1093/hmg/dds301
PMCID: PMC3471395  PMID: 22843504
13.  High-functioning autism spectrum disorder and fragile X syndrome: report of two affected sisters 
Molecular Autism  2012;3:5.
Background
Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability (ID), as well as the most frequent monogenic cause of autism spectrum disorder (ASD). Men with FXS exhibit ID, often associated with autistics features, whereas women heterozygous for the full mutation are typically less severely affected; about half have a normal or borderline intelligence quotient (IQ). Previous findings have shown a strong association between ID and ASD in both men and women with FXS. We describe here the case of two sisters with ASD and FXS but without ID. One of the sisters presented with high-functioning autism, the other one with pervasive developmental disorder not otherwise specified and low normal IQ.
Methods
The methylation status of the mutated FMR1 alleles was examined by Southern blot and methylation-sensitive polymerase chain reaction. The X-chromosome inactivation was determined by analyzing the methylation status of the androgen receptor at Xq12.
Results
Both sisters carried a full mutation in the FMR1 gene, with complete methylation and random X chromosome inactivation. We present the phenotype of the two sisters and other family members.
Conclusions
These findings suggest that autistic behaviors and cognitive impairment can manifest as independent traits in FXS. Mutations in FMR1, known to cause syndromic autism, may also contribute to the etiology of high-functioning, non-syndromic ASD, particularly in women. Thus, screening for FXS in patients with ASD should not be limited to those with comorbid ID.
doi:10.1186/2040-2392-3-5
PMCID: PMC3444384  PMID: 22738402
Autism spectrum disorders; Female; Fragile X syndrome; Intellectual disability
14.  Mutation Screening of the PTEN Gene in Patients With Autism Spectrum Disorders and Macrocephaly 
American Journal of Medical Genetics  2007;144B(4):484-491.
Mutations in the PTEN gene are associated with a broad spectrum of disorders, including Cowden syndrome (CS), Bannayan–Riley–Ruvalcaba syndrome, Proteus syndrome, and Lhermitte–Duclos disease. In addition, PTENmutations have been described in a few patients with autism spectrum disorders (ASDs) and macrocephaly. In this study, we screened the PTEN gene for mutations and deletions in 88 patients with ASDs and macrocephaly (defined as ≥2 SD above the mean). Mutation analysis was performed by direct sequencing of all exons and flanking regions, as well as the promoter region. Dosage analysis of PTEN was carried out using multiplex ligation-dependent probe amplification (MLPA). No partial or whole gene deletions were observed. We identified a de novo missense mutation (D326N) in a highly conserved amino acid in a 5-year-old boy with autism, mental retardation, language delay, extreme macrocephaly (+9.6 SD) and polydactyly of both feet. Polydactyly has previously been described in two patients with Lhermitte–Duclos disease and CS and is thus likely to be a rare sign of PTEN mutations. Our findings suggest that PTEN mutations are a relatively infrequent cause of ASDs with macrocephaly. Screening of PTEN mutations is warranted in patients with autism and pronounced macrocephaly, even in the absence of other features of PTEN-related tumor syndromes.
doi:10.1002/ajmg.b.30493
PMCID: PMC3381648  PMID: 17427195
Cowden syndrome; Bannayan–Riley–Ruvalcaba syndrome; polydactyly; sequence analysis; multiplex ligation-dependent probe amplification
15.  A family with autism and rare copy number variants disrupting the Duchenne/Becker muscular dystrophy gene DMD and TRPM3 
Autism spectrum disorder is a genetically complex and clinically heterogeneous neurodevelopmental disorder. A recent study by the Autism Genome Project (AGP) used 1M single nucleotide polymorphism (SNP) arrays to show that rare genic copy number variants (CNVs), possibly acting in tandem, play a significant role in the genetic aetiology of this condition. In this study, we describe the phenotypic and genomic characterisation of a multiplex autism family from the AGP study that was found to harbour a duplication of exons 31-44 of the Duchenne/Becker muscular dystrophy gene DMD and also a rare deletion involving exons 1-9 of TRPM3. Further characterisation of these extremely rare CNVs was carried out using quantitative PCR, fluorescent in situ hybridization, long-range PCR amplification and sequencing of junction fragments. The maternal chrX:32,097,213-32,321,945 tandem duplication and paternal chr9:72,480,413-73,064,196 deletion (NCBI build 36 coordinates) were transmitted to both affected boys, potentially signifying a multi-hit mechanism. The DMD reading frame rule predicts a Becker phenotype, characterized by later onset and milder symptoms. When last evaluated, neither child had developed signs of muscular dystrophy. These data are consistent with a degree of comorbidity between autism and muscular dystrophy and suggest that genomic background as well as the position of the mutation within the DMD gene may impact on the neurological correlates of Duchenne/Becker muscular dystrophy. Finally, communicating unexpected findings such as these back to families raises a number of ethical questions, which are discussed.
doi:10.1007/s11689-011-9076-5
PMCID: PMC3105230  PMID: 21484199
Autism; Becker; Duchenne; CNV; comorbid; DMD
16.  Clinical utility gene card for: Deletion 22q13 syndrome 
doi:10.1038/ejhg.2010.193
PMCID: PMC3060317  PMID: 21150887
17.  Optimizing the phenotyping of rodent ASD models: enrichment analysis of mouse and human neurobiological phenotypes associated with high-risk autism genes identifies morphological, electrophysiological, neurological, and behavioral features 
Molecular Autism  2012;3:1.
Background
There is interest in defining mouse neurobiological phenotypes useful for studying autism spectrum disorders (ASD) in both forward and reverse genetic approaches. A recurrent focus has been on high-order behavioral analyses, including learning and memory paradigms and social paradigms. However, well-studied mouse models, including for example Fmr1 knockout mice, do not show dramatic deficits in such high-order phenotypes, raising a question as to what constitutes useful phenotypes in ASD models.
Methods
To address this, we made use of a list of 112 disease genes etiologically involved in ASD to survey, on a large scale and with unbiased methods as well as expert review, phenotypes associated with a targeted disruption of these genes in mice, using the Mammalian Phenotype Ontology database. In addition, we compared the results with similar analyses for human phenotypes.
Findings
We observed four classes of neurobiological phenotypes associated with disruption of a large proportion of ASD genes, including: (1) Changes in brain and neuronal morphology; (2) electrophysiological changes; (3) neurological changes; and (4) higher-order behavioral changes. Alterations in brain and neuronal morphology represent quantitative measures that can be more widely adopted in models of ASD to understand cellular and network changes. Interestingly, the electrophysiological changes differed across different genes, indicating that excitation/inhibition imbalance hypotheses for ASD would either have to be so non-specific as to be not falsifiable, or, if specific, would not be supported by the data. Finally, it was significant that in analyses of both mouse and human databases, many of the behavioral alterations were neurological changes, encompassing sensory alterations, motor abnormalities, and seizures, as opposed to higher-order behavioral changes in learning and memory and social behavior paradigms.
Conclusions
The results indicated that mutations in ASD genes result in defined groups of changes in mouse models and support a broad neurobiological approach to phenotyping rodent models for ASD, with a focus on biochemistry and molecular biology, brain and neuronal morphology, and electrophysiology, as well as both neurological and additional behavioral analyses. Analysis of human phenotypes associated with these genes reinforced these conclusions, supporting face validity for these approaches to phenotyping of ASD models. Such phenotyping is consistent with the successes in Fmr1 knockout mice, in which morphological changes recapitulated human findings and electrophysiological deficits resulted in molecular insights that have since led to clinical trials. We propose both broad domains and, based on expert review of more than 50 publications in each of the four neurobiological domains, specific tests to be applied to rodent models of ASD.
doi:10.1186/2040-2392-3-1
PMCID: PMC3337792  PMID: 22348382
Systems biology; mouse behavior; autism; autism spectrum disorders; genetically modified mice; forward genetics; reverse genetics
18.  Genetic and Functional Analyses of SHANK2 Mutations Suggest a Multiple Hit Model of Autism Spectrum Disorders 
PLoS Genetics  2012;8(2):e1002521.
Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While many rare variants in synaptic proteins have been identified in patients with ASD, little is known about their effects at the synapse and their interactions with other genetic variations. Here, following the discovery of two de novo SHANK2 deletions by the Autism Genome Project, we identified a novel 421 kb de novo SHANK2 deletion in a patient with autism. We then sequenced SHANK2 in 455 patients with ASD and 431 controls and integrated these results with those reported by Berkel et al. 2010 (n = 396 patients and n = 659 controls). We observed a significant enrichment of variants affecting conserved amino acids in 29 of 851 (3.4%) patients and in 16 of 1,090 (1.5%) controls (P = 0.004, OR = 2.37, 95% CI = 1.23–4.70). In neuronal cell cultures, the variants identified in patients were associated with a reduced synaptic density at dendrites compared to the variants only detected in controls (P = 0.0013). Interestingly, the three patients with de novo SHANK2 deletions also carried inherited CNVs at 15q11–q13 previously associated with neuropsychiatric disorders. In two cases, the nicotinic receptor CHRNA7 was duplicated and in one case the synaptic translation repressor CYFIP1 was deleted. These results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the “multiple hit model” for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD.
Author Summary
Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While mutations in several genes have been identified in patients with ASD, little is known about their effects on neuronal function and their interaction with other genetic variations. Using a combination of genetic and functional approaches, we identified novel SHANK2 mutations including a de novo loss of one copy of the SHANK2 gene in a patient with autism and several mutations observed in patients that reduced neuronal cell contacts in vitro. Further genomic analysis of three patients carrying de novo SHANK2 deletions identified additional rare genomic imbalances previously associated with neuropsychiatric disorders. Taken together, these results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the “multiple hit model” for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD.
doi:10.1371/journal.pgen.1002521
PMCID: PMC3276563  PMID: 22346768
19.  A novel approach of homozygous haplotype sharing identifies candidate genes in autism spectrum disorder 
Casey, Jillian P. | Magalhaes, Tiago | Conroy, Judith M. | Regan, Regina | Shah, Naisha | Anney, Richard | Shields, Denis C. | Abrahams, Brett S. | Almeida, Joana | Bacchelli, Elena | Bailey, Anthony J. | Baird, Gillian | Battaglia, Agatino | Berney, Tom | Bolshakova, Nadia | Bolton, Patrick F. | Bourgeron, Thomas | Brennan, Sean | Cali, Phil | Correia, Catarina | Corsello, Christina | Coutanche, Marc | Dawson, Geraldine | de Jonge, Maretha | Delorme, Richard | Duketis, Eftichia | Duque, Frederico | Estes, Annette | Farrar, Penny | Fernandez, Bridget A. | Folstein, Susan E. | Foley, Suzanne | Fombonne, Eric | Freitag, Christine M. | Gilbert, John | Gillberg, Christopher | Glessner, Joseph T. | Green, Jonathan | Guter, Stephen J. | Hakonarson, Hakon | Holt, Richard | Hughes, Gillian | Hus, Vanessa | Igliozzi, Roberta | Kim, Cecilia | Klauck, Sabine M. | Kolevzon, Alexander | Lamb, Janine A. | Leboyer, Marion | Le Couteur, Ann | Leventhal, Bennett L. | Lord, Catherine | Lund, Sabata C. | Maestrini, Elena | Mantoulan, Carine | Marshall, Christian R. | McConachie, Helen | McDougle, Christopher J. | McGrath, Jane | McMahon, William M. | Merikangas, Alison | Miller, Judith | Minopoli, Fiorella | Mirza, Ghazala K. | Munson, Jeff | Nelson, Stanley F. | Nygren, Gudrun | Oliveira, Guiomar | Pagnamenta, Alistair T. | Papanikolaou, Katerina | Parr, Jeremy R. | Parrini, Barbara | Pickles, Andrew | Pinto, Dalila | Piven, Joseph | Posey, David J. | Poustka, Annemarie | Poustka, Fritz | Ragoussis, Jiannis | Roge, Bernadette | Rutter, Michael L. | Sequeira, Ana F. | Soorya, Latha | Sousa, Inês | Sykes, Nuala | Stoppioni, Vera | Tancredi, Raffaella | Tauber, Maïté | Thompson, Ann P. | Thomson, Susanne | Tsiantis, John | Van Engeland, Herman | Vincent, John B. | Volkmar, Fred | Vorstman, Jacob A. S. | Wallace, Simon | Wang, Kai | Wassink, Thomas H. | White, Kathy | Wing, Kirsty | Wittemeyer, Kerstin | Yaspan, Brian L. | Zwaigenbaum, Lonnie | Betancur, Catalina | Buxbaum, Joseph D. | Cantor, Rita M. | Cook, Edwin H. | Coon, Hilary | Cuccaro, Michael L. | Geschwind, Daniel H. | Haines, Jonathan L. | Hallmayer, Joachim | Monaco, Anthony P. | Nurnberger, John I. | Pericak-Vance, Margaret A. | Schellenberg, Gerard D. | Scherer, Stephen W. | Sutcliffe, James S. | Szatmari, Peter | Vieland, Veronica J. | Wijsman, Ellen M. | Green, Andrew | Gill, Michael | Gallagher, Louise | Vicente, Astrid | Ennis, Sean
Human Genetics  2011;131(4):565-579.
Autism spectrum disorder (ASD) is a highly heritable disorder of complex and heterogeneous aetiology. It is primarily characterized by altered cognitive ability including impaired language and communication skills and fundamental deficits in social reciprocity. Despite some notable successes in neuropsychiatric genetics, overall, the high heritability of ASD (~90%) remains poorly explained by common genetic risk variants. However, recent studies suggest that rare genomic variation, in particular copy number variation, may account for a significant proportion of the genetic basis of ASD. We present a large scale analysis to identify candidate genes which may contain low-frequency recessive variation contributing to ASD while taking into account the potential contribution of population differences to the genetic heterogeneity of ASD. Our strategy, homozygous haplotype (HH) mapping, aims to detect homozygous segments of identical haplotype structure that are shared at a higher frequency amongst ASD patients compared to parental controls. The analysis was performed on 1,402 Autism Genome Project trios genotyped for 1 million single nucleotide polymorphisms (SNPs). We identified 25 known and 1,218 novel ASD candidate genes in the discovery analysis including CADM2, ABHD14A, CHRFAM7A, GRIK2, GRM3, EPHA3, FGF10, KCND2, PDZK1, IMMP2L and FOXP2. Furthermore, 10 of the previously reported ASD genes and 300 of the novel candidates identified in the discovery analysis were replicated in an independent sample of 1,182 trios. Our results demonstrate that regions of HH are significantly enriched for previously reported ASD candidate genes and the observed association is independent of gene size (odds ratio 2.10). Our findings highlight the applicability of HH mapping in complex disorders such as ASD and offer an alternative approach to the analysis of genome-wide association data.
Electronic supplementary material
The online version of this article (doi:10.1007/s00439-011-1094-6) contains supplementary material, which is available to authorized users.
doi:10.1007/s00439-011-1094-6
PMCID: PMC3303079  PMID: 21996756
20.  A family with autism and rare copy number variants disrupting the Duchenne/Becker muscular dystrophy gene DMD and TRPM3 
Autism spectrum disorder is a genetically complex and clinically heterogeneous neurodevelopmental disorder. A recent study by the Autism Genome Project (AGP) used 1M single-nucleotide polymorphism arrays to show that rare genic copy number variants (CNVs), possibly acting in tandem, play a significant role in the genetic aetiology of this condition. In this study, we describe the phenotypic and genomic characterisation of a multiplex autism family from the AGP study that was found to harbour a duplication of exons 31–44 of the Duchenne/Becker muscular dystrophy gene DMD and also a rare deletion involving exons 1–9 of TRPM3. Further characterisation of these extremely rare CNVs was carried out using quantitative PCR, fluorescent in situ hybridisation, long-range PCR amplification and sequencing of junction fragments. The maternal chrX:32,097,213-32,321,945 tandem duplication and paternal chr9:72,480,413-73,064,196 deletion (NCBI build 36 coordinates) were transmitted to both affected boys, potentially signifying a multi-hit mechanism. The DMD reading frame rule predicts a Becker phenotype, characterised by later onset and milder symptoms. When last evaluated, neither child had developed signs of muscular dystrophy. These data are consistent with a degree of comorbidity between autism and muscular dystrophy and suggest that genomic background as well as the position of the mutation within the DMD gene may impact on the neurological correlates of Duchenne/Becker muscular dystrophy. Finally, communicating unexpected findings such as these back to families raises a number of ethical questions, which are discussed.
Electronic supplementary material
The online version of this article (doi:10.1007/s11689-011-9076-5) contains supplementary material, which is available to authorized users.
doi:10.1007/s11689-011-9076-5
PMCID: PMC3105230  PMID: 21484199
Autism; Becker; Duchenne; CNV; Comorbid; DMD
21.  A family with autism and rare copy number variants disrupting the Duchenne/Becker muscular dystrophy gene DMD and TRPM3 
Autism spectrum disorder is a genetically complex and clinically heterogeneous neurodevelopmental disorder. A recent study by the Autism Genome Project (AGP) used 1M single-nucleotide polymorphism arrays to show that rare genic copy number variants (CNVs), possibly acting in tandem, play a significant role in the genetic aetiology of this condition. In this study, we describe the phenotypic and genomic characterisation of a multiplex autism family from the AGP study that was found to harbour a duplication of exons 31–44 of the Duchenne/Becker muscular dystrophy gene DMD and also a rare deletion involving exons 1–9 of TRPM3. Further characterisation of these extremely rare CNVs was carried out using quantitative PCR, fluorescent in situ hybridisation, long-range PCR amplification and sequencing of junction fragments. The maternal chrX:32,097,213-32,321,945 tandem duplication and paternal chr9:72,480,413-73,064,196 deletion (NCBI build 36 coordinates) were transmitted to both affected boys, potentially signifying a multi-hit mechanism. The DMD reading frame rule predicts a Becker phenotype, characterised by later onset and milder symptoms. When last evaluated, neither child had developed signs of muscular dystrophy. These data are consistent with a degree of comorbidity between autism and muscular dystrophy and suggest that genomic background as well as the position of the mutation within the DMD gene may impact on the neurological correlates of Duchenne/Becker muscular dystrophy. Finally, communicating unexpected findings such as these back to families raises a number of ethical questions, which are discussed.
Electronic supplementary material
The online version of this article (doi:10.1007/s11689-011-9076-5) contains supplementary material, which is available to authorized users.
doi:10.1007/s11689-011-9076-5
PMCID: PMC3105230  PMID: 21484199
Autism; Becker; Duchenne; CNV; Comorbid; DMD
22.  Functional Impact of Global Rare Copy Number Variation in Autism Spectrum Disorder 
Pinto, Dalila | Pagnamenta, Alistair T. | Klei, Lambertus | Anney, Richard | Merico, Daniele | Regan, Regina | Conroy, Judith | Magalhaes, Tiago R. | Correia, Catarina | Abrahams, Brett S. | Almeida, Joana | Bacchelli, Elena | Bader, Gary D. | Bailey, Anthony J. | Baird, Gillian | Battaglia, Agatino | Berney, Tom | Bolshakova, Nadia | Bölte, Sven | Bolton, Patrick F. | Bourgeron, Thomas | Brennan, Sean | Brian, Jessica | Bryson, Susan E. | Carson, Andrew R. | Casallo, Guillermo | Casey, Jillian | Cochrane, Lynne | Corsello, Christina | Crawford, Emily L. | Crossett, Andrew | Dawson, Geraldine | de Jonge, Maretha | Delorme, Richard | Drmic, Irene | Duketis, Eftichia | Duque, Frederico | Estes, Annette | Farrar, Penny | Fernandez, Bridget A. | Filipa, Ana | Folstein, Susan E. | Fombonne, Eric | Freitag, Christine M. | Gilbert, John | Gillberg, Christopher | Glessner, Joseph T. | Goldberg, Jeremy | Green, Andrew | Green, Jonathan | Guter, Stephen J. | Hakonarson, Hakon | Heron, Elizabeth A. | Hill, Matthew | Holt, Richard | Howe, Jennifer L. | Hughes, Gillian | Hus, Vanessa | Igliozzi, Roberta | Kim, Cecilia | Klauck, Sabine M. | Kolevzon, Alexander | Korvatska, Olena | Kustanovich, Vlad | Lajonchere, Clara M. | Lamb, Janine A. | Laskawiec, Magdalena | Leboyer, Marion | Le Couteur, Ann | Leventhal, Bennett L. | Lionel, Anath C. | Liu, Xiao-Qing | Lord, Catherine | Lotspeich, Linda | Lund, Sabata C. | Maestrini, Elena | Mahoney, William | Mantoulan, Carine | Marshall, Christian R. | McConachie, Helen | McDougle, Christopher J. | McGrath, Jane | McMahon, William M. | Merikangas, Alison | Migita, Ohsuke | Minshew, Nancy J. | Mirza, Ghazala K. | Munson, Jeff | Nelson, Stanley F. | Noakes, Carolyn | Noor, Abdul | Nygren, Gudrun | Oliveira, Guiomar | Papanikolaou, Katerina | Parr, Jeremy R. | Parrini, Barbara | Paton, Tara | Pickles, Andrew | Pilorge, Marion | Piven, Joseph | Ponting, Chris P. | Posey, David J. | Poustka, Annemarie | Poustka, Fritz | Prasad, Aparna | Ragoussis, Jiannis | Renshaw, Katy | Rickaby, Jessica | Roberts, Wendy | Roeder, Kathryn | Roge, Bernadette | Rutter, Michael L. | Bierut, Laura J. | Rice, John P. | Consortium, SAGE | Salt, Jeff | Sansom, Katherine | Sato, Daisuke | Segurado, Ricardo | Senman, Lili | Shah, Naisha | Sheffield, Val C. | Soorya, Latha | Sousa, Inês | Stein, Olaf | Stoppioni, Vera | Strawbridge, Christina | Tancredi, Raffaella | Tansey, Katherine | Thiruvahindrapduram, Bhooma | Thompson, Ann P. | Thomson, Susanne | Tryfon, Ana | Tsiantis, John | Van Engeland, Herman | Vincent, John B. | Volkmar, Fred | Wallace, Simon | Wang, Kai | Wang, Zhouzhi | Wassink, Thomas H. | Webber, Caleb | Wing, Kirsty | Wittemeyer, Kerstin | Wood, Shawn | Wu, Jing | Yaspan, Brian L. | Zurawiecki, Danielle | Zwaigenbaum, Lonnie | Buxbaum, Joseph D. | Cantor, Rita M. | Cook, Edwin H. | Coon, Hilary | Cuccaro, Michael L. | Devlin, Bernie | Ennis, Sean | Gallagher, Louise | Geschwind, Daniel H. | Gill, Michael | Haines, Jonathan L. | Hallmayer, Joachim | Miller, Judith | Monaco, Anthony P. | Nurnberger, John I. | Paterson, Andrew D. | Pericak-Vance, Margaret A. | Schellenberg, Gerard D. | Szatmari, Peter | Vicente, Astrid M. | Vieland, Veronica J. | Wijsman, Ellen M. | Scherer, Stephen W. | Sutcliffe, James S. | Betancur, Catalina
Nature  2010;466(7304):368-372.
The autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in reciprocal social interaction and communication, and the presence of restricted and repetitive behaviors1. Individuals with an ASD vary greatly in cognitive development, which can range from above average to intellectual disability (ID)2. While ASDs are known to be highly heritable (~90%)3, the underlying genetic determinants are still largely unknown. Here, we analyzed the genome-wide characteristics of rare (<1% frequency) copy number variation (CNV) in ASD using dense genotyping arrays. When comparing 996 ASD individuals of European ancestry to 1,287 matched controls, cases were found to carry a higher global burden of rare, genic CNVs (1.19 fold, P= 0.012), especially so for loci previously implicated in either ASD and/or intellectual disability (1.69 fold, P= 3.4×10−4). Among the CNVs, there were numerous de novo and inherited events, sometimes in combination in a given family, implicating many novel ASD genes like SHANK2, SYNGAP1, DLGAP2 and the X-linked DDX53-PTCHD1 locus. We also discovered an enrichment of CNVs disrupting functional gene-sets involved in cellular proliferation, projection and motility, and GTPase/Ras signaling. Our results reveal many new genetic and functional targets in ASD that may lead to final connected pathways.
doi:10.1038/nature09146
PMCID: PMC3021798  PMID: 20531469
23.  Molecular characterization of a de novo 6q24.2q25.3 duplication interrupting UTRN in a patient with arthrogryposis 
Chromosome 6q duplications have been documented repeatedly, allowing the delineation of a “6q duplication syndrome”, characterized by hypertelorism, downslanting palpebral fissures, tented upper lip, short neck, severe mental and growth retardation, and joint contractures. Most reported cases result from malsegregation of a reciprocal translocation leading to a terminal 6q duplication and partial monosomy of another chromosome. Only 11 cases of de novo pure duplication have been reported so far. The breakpoints do not appear to be recurrent, but in most cases they have not been characterized molecularly, precluding genotype-phenotype correlation. We report on an 8-year-old girl with a phenotype consistent with mild 6q duplication syndrome, including characteristic physical findings, mild mental retardation, and joint contractures. She carries a 13 Mb de novo 6q24.2q25.3 duplication, diagnosed by high-resolution karyotype and confirmed by array-CGH. Molecular characterization of the duplicated segment with quantitative PCR showed that the proximal breakpoint is localized within the UTRN gene, encoding utrophin, the autosomal homologue of dystrophin. We discuss the possible implication of UTRN in arthrogryposis associated with duplications spanning the 6q23q26 region.
doi:10.1002/ajmg.a.33433
PMCID: PMC2962443  PMID: 20583184
Arthrogryposis; complications; genetics; Child, Preschool; Chromosome Aberrations; Chromosome Banding; Chromosome Mapping; Chromosomes, Human, Pair 6; genetics; Comparative Genomic Hybridization; Female; Gene Duplication; Hand Deformities, Congenital; complications; radiography; Humans; In Situ Hybridization, Fluorescence; Infant; Infant, Newborn; Karyotyping; Polymerase Chain Reaction; Pregnancy; Utrophin; genetics; 6q duplication syndrome; joint contracture; utrophin; array-CGH; qPCR
24.  A genome-wide scan for common alleles affecting risk for autism 
Anney, Richard | Klei, Lambertus | Pinto, Dalila | Regan, Regina | Conroy, Judith | Magalhaes, Tiago R. | Correia, Catarina | Abrahams, Brett S. | Sykes, Nuala | Pagnamenta, Alistair T. | Almeida, Joana | Bacchelli, Elena | Bailey, Anthony J. | Baird, Gillian | Battaglia, Agatino | Berney, Tom | Bolshakova, Nadia | Bölte, Sven | Bolton, Patrick F. | Bourgeron, Thomas | Brennan, Sean | Brian, Jessica | Carson, Andrew R. | Casallo, Guillermo | Casey, Jillian | Chu, Su H. | Cochrane, Lynne | Corsello, Christina | Crawford, Emily L. | Crossett, Andrew | Dawson, Geraldine | de Jonge, Maretha | Delorme, Richard | Drmic, Irene | Duketis, Eftichia | Duque, Frederico | Estes, Annette | Farrar, Penny | Fernandez, Bridget A. | Folstein, Susan E. | Fombonne, Eric | Freitag, Christine M. | Gilbert, John | Gillberg, Christopher | Glessner, Joseph T. | Goldberg, Jeremy | Green, Jonathan | Guter, Stephen J. | Hakonarson, Hakon | Heron, Elizabeth A. | Hill, Matthew | Holt, Richard | Howe, Jennifer L. | Hughes, Gillian | Hus, Vanessa | Igliozzi, Roberta | Kim, Cecilia | Klauck, Sabine M. | Kolevzon, Alexander | Korvatska, Olena | Kustanovich, Vlad | Lajonchere, Clara M. | Lamb, Janine A. | Laskawiec, Magdalena | Leboyer, Marion | Le Couteur, Ann | Leventhal, Bennett L. | Lionel, Anath C. | Liu, Xiao-Qing | Lord, Catherine | Lotspeich, Linda | Lund, Sabata C. | Maestrini, Elena | Mahoney, William | Mantoulan, Carine | Marshall, Christian R. | McConachie, Helen | McDougle, Christopher J. | McGrath, Jane | McMahon, William M. | Melhem, Nadine M. | Merikangas, Alison | Migita, Ohsuke | Minshew, Nancy J. | Mirza, Ghazala K. | Munson, Jeff | Nelson, Stanley F. | Noakes, Carolyn | Noor, Abdul | Nygren, Gudrun | Oliveira, Guiomar | Papanikolaou, Katerina | Parr, Jeremy R. | Parrini, Barbara | Paton, Tara | Pickles, Andrew | Piven, Joseph | Posey, David J | Poustka, Annemarie | Poustka, Fritz | Prasad, Aparna | Ragoussis, Jiannis | Renshaw, Katy | Rickaby, Jessica | Roberts, Wendy | Roeder, Kathryn | Roge, Bernadette | Rutter, Michael L. | Bierut, Laura J. | Rice, John P. | Salt, Jeff | Sansom, Katherine | Sato, Daisuke | Segurado, Ricardo | Senman, Lili | Shah, Naisha | Sheffield, Val C. | Soorya, Latha | Sousa, Inês | Stoppioni, Vera | Strawbridge, Christina | Tancredi, Raffaella | Tansey, Katherine | Thiruvahindrapduram, Bhooma | Thompson, Ann P. | Thomson, Susanne | Tryfon, Ana | Tsiantis, John | Van Engeland, Herman | Vincent, John B. | Volkmar, Fred | Wallace, Simon | Wang, Kai | Wang, Zhouzhi | Wassink, Thomas H. | Wing, Kirsty | Wittemeyer, Kerstin | Wood, Shawn | Yaspan, Brian L. | Zurawiecki, Danielle | Zwaigenbaum, Lonnie | Betancur, Catalina | Buxbaum, Joseph D. | Cantor, Rita M. | Cook, Edwin H. | Coon, Hilary | Cuccaro, Michael L. | Gallagher, Louise | Geschwind, Daniel H. | Gill, Michael | Haines, Jonathan L. | Miller, Judith | Monaco, Anthony P. | Nurnberger, John I. | Paterson, Andrew D. | Pericak-Vance, Margaret A. | Schellenberg, Gerard D. | Scherer, Stephen W. | Sutcliffe, James S. | Szatmari, Peter | Vicente, Astrid M. | Vieland, Veronica J. | Wijsman, Ellen M. | Devlin, Bernie | Ennis, Sean | Hallmayer, Joachim
Human Molecular Genetics  2010;19(20):4072-4082.
Although autism spectrum disorders (ASDs) have a substantial genetic basis, most of the known genetic risk has been traced to rare variants, principally copy number variants (CNVs). To identify common risk variation, the Autism Genome Project (AGP) Consortium genotyped 1558 rigorously defined ASD families for 1 million single-nucleotide polymorphisms (SNPs) and analyzed these SNP genotypes for association with ASD. In one of four primary association analyses, the association signal for marker rs4141463, located within MACROD2, crossed the genome-wide association significance threshold of P < 5 × 10−8. When a smaller replication sample was analyzed, the risk allele at rs4141463 was again over-transmitted; yet, consistent with the winner's curse, its effect size in the replication sample was much smaller; and, for the combined samples, the association signal barely fell below the P < 5 × 10−8 threshold. Exploratory analyses of phenotypic subtypes yielded no significant associations after correction for multiple testing. They did, however, yield strong signals within several genes, KIAA0564, PLD5, POU6F2, ST8SIA2 and TAF1C.
doi:10.1093/hmg/ddq307
PMCID: PMC2947401  PMID: 20663923
25.  Mutation screening of NOS1AP gene in a large sample of psychiatric patients and controls 
BMC Medical Genetics  2010;11:108.
Background
The gene encoding carboxyl-terminal PDZ ligand of neuronal nitric oxide synthase (NOS1AP) is located on chromosome 1q23.3, a candidate region for schizophrenia, autism spectrum disorders (ASD) and obsessive-compulsive disorder (OCD). Previous genetic and functional studies explored the role of NOS1AP in these psychiatric conditions, but only a limited number explored the sequence variability of NOS1AP.
Methods
We analyzed the coding sequence of NOS1AP in a large population (n = 280), including patients with schizophrenia (n = 72), ASD (n = 81) or OCD (n = 34), and in healthy volunteers controlled for the absence of personal or familial history of psychiatric disorders (n = 93).
Results
Two non-synonymous variations, V37I and D423N were identified in two families, one with two siblings with OCD and the other with two brothers with ASD. These rare variations apparently segregate with the presence of psychiatric conditions.
Conclusions
Coding variations of NOS1AP are relatively rare in patients and controls. Nevertheless, we report the first non-synonymous variations within the human NOS1AP gene that warrant further genetic and functional investigations to ascertain their roles in the susceptibility to psychiatric disorders.
doi:10.1186/1471-2350-11-108
PMCID: PMC2919462  PMID: 20602773

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