Aortic aneurysm and dissection cause significant morbidity and mortality. There are several known single gene disorders that predispose to isolated aortic disease and eventually aneurysm and dissection. FBN1 mutations are associated with multiple clinical phenotypes, including Marfan syndrome (MFS), MASS phenotype, and familial ectopia lentis, but rarely with isolated aortic aneurysm and dissection. In this report, we describe three patients who presented with primary descending thoracic aortic dissection and who were found to have an FBN1 mutation. None of the patients fulfilled clinical criteria for the diagnosis of MFS, and all had few or none of the skeletal features typical of the condition. Two patients had a history of long-term hypertension, and such a history was suspected in the third patient. These observations suggest that some individuals with FBN1 mutations have significant aortic disease involvement of other systems that is typical of FBN1 mutation-related syndromes. Superimposed risk factors, such as hypertension, may weaken the aortic wall and eventually lead to aortic dissection. Given that the cost continues to decrease, we suggest that diagnostic DNA sequencing for FBN1 mutations in patients with thoracic aortic aneurysms and dissection may be a practical clinical step in evaluating such patients and at-risk family members.

Various forms of pigmentary dysplasias have been known to be associated with chromosomal mosaicism. One of these disorders, known as phylloid hypomelanosis, has been found to be predominantly associated with abnormalities in chromosome 13. Most of the reported literature involves mosaic trisomy 13 with clinical evidence of abnormal pigmentation in the form of leaf-like or oblong achromic macules following Blaschko’s lines. Here, we report on an 8-year-old girl with phylloid hypomelanosis and precocious puberty who was found to have mosaicism for tetrasomy 13q in the form of inverted dup(13)(q21) on her skin fibroblasts as well as peripheral blood karyotype. A higher resolution (244K) chromosomal microarray was done on DNA from skin fibroblasts confirming the breakpoint and gain of distal 13q, which made her tetrasomic for 13q21-qter. This is the first-ever reported association of tetrasomy 13q with phylloid hypomelanosis and precocious puberty. Our report further emphasizes the need to exclude any type of abnormalities of chromosome 13 in patients with phylloid hypopigmentation.

Smooth muscle cells (SMCs) contract to perform many physiological functions, including regulation of blood flow and pressure in arteries, contraction of the pupils, peristalsis of the gut and voiding of the bladder. SMC lineage in these organs is characterized by cellular expression of the SMC isoform of α-actin, encoded by the ACTA2 gene. We report here on a unique and de novo mutation in ACTA2, R179H, that causes a syndrome characterized by dysfunction of SMCs throughout the body, leading to aortic and cerebrovascular disease, fixed dilated pupils, hypotonic bladder, malrotation and hypoperistalsis of the gut and pulmonary hypertension.

Individuals with alleles containing 55–200 CGG repeats in the fragile X mental retardation (FMR1) gene are premutation carriers. The premutation allele has been shown to lead to a number of types of clinical involvement, including shyness, anxiety, social deficits, attention deficit hyperactivity disorder (ADHD) and executive function deficits. Some of these problems could be due to mild deficits of the fragile X protein (FMRP) and a possible developmental effect of the elevated FMR1 mRNA observed in carriers. In addition, two abnormal phenotypes specific to the premutation have been described. Primary ovarian insufficiency (FXPOI), defined by cessation of menses prior to age 40, occurs in 20% of females with the premutation. The other phenotype, fragile X-associated tremor/ataxia syndrome (FXTAS), affects some older adult premutation carriers.

Premutation females typically have one expanded allele (≥ 55 CGG repeats) and one normal allele (≤ 54 CGG repeats). This study describes the cognitive, behavioral and molecular profile of a female with two alleles in the premutation range (60 and 67 CGG repeats) in comparison to her brother with a similar premutation size (65 CGG repeats). Both exhibited high IQ scores, anxiety, and some physical features associated with fragile X syndrome. This comparison allows us to examine the effect of the premutation in this male-female pair while controlling for environmental and background genetic factors.

Atrioventricular septal defects (AVSDs) are a frequent but not universal component of Down syndrome (DS), while AVSDs in otherwise normal individuals have no well-defined genetic basis. The contribution of copy number variation (CNV) to specific congenital heart disease (CHD) phenotypes including AVSD is unknown. We hypothesized that de novo CNVs on chromosome 21 might cause isolated sporadic AVSDs, and separately that CNVs throughout the genome might constitute an additional genetic risk factor for AVSD in patients with DS. We utilized a custom oligonucleotide arrays targeted to CNV hotspots that are flanked by large duplicated segments of high sequence identity. We assayed 29 euploid and 50 DS individuals with AVSD, and compared to general population controls. In patients with isolated-sporadic AVSD we identified two large unique deletions outside of chromosome 21 not seen in the expanded set of 8,635 controls, each overlapping with larger deletions associated with similar CHD reported in the DECIPHER database. There was a small duplication in one patient with DS and AVSD. We conclude that isolated sporadic AVSDs may be occasionally associated with large de novo genomic structural variation outside of chromosome 21. The absence of CNVs on chromosome 21 in patients with isolated sporadic AVSD suggests that sub-chromosomal duplications or deletions of greater than 150 kbp on chromosome 21 do not cause sporadic AVSDs. Large CNVs do not appear to be an additive risk factor for AVSD in the DS population.

Angelman syndrome (AS) is a neurodevelopmental disorder caused by a lack of expression of the maternal copy of UBE3A. Although the “classic” features of AS are well described, few large-scale studies have delineated the clinical features in AS. We present baseline data from 92 children with a molecular diagnosis of AS between 5 and 60 months old who are enrolled in the National Institutes of Health Rare Diseases Clinical Research Network Angelman Syndrome Natural History Study from January 2006 to March 2008. Seventy-four percent of participants had deletions, 14% had either uniparental disomy (UPD) or imprinting defects, and 12% had UBE3A mutations. Participants with UPD/imprinting defects were heavier (P = 0.0002), while those with deletions were lighter, than the general population (P < 0.0001). Twenty out of 92 participants were underweight, all of whom had deletions or UBE3A mutations. Eight out of 92 participants (6/13 (46%) with UPD/imprinting defects and 2/11 (18%) with UBE3A mutations) were obese. Seventy-four out of 92 participants (80%) had absolute or relative microcephaly. No participant was macrocephalic. The most common behavioral findings were mouthing behavior (95%), short attention span (92%), ataxic or broad-based gait (88%), history of sleep difficulties (80%), and fascination with water (75%). Frequent, easily provoked laughter was observed in 60%. Clinical seizures were reported in 65% of participants but all electroencephalograms (EEGs) were abnormal. We conclude that the most characteristic feature of AS is the neurobehavioral phenotype, but specific EEG findings are highly sensitive for AS. Obesity is common among those with UPD/imprinting defects.

Fibrochondrogenesis is a severe, recessively inherited skeletal dysplasia shown to result from mutations in the gene encoding the proα1(XI) chain of type XI collagen, COL11A1. The first of two cases reported here was the affected offspring of first cousins and sequence analysis excluded mutations in COL11A1. Consequently, whole-genome SNP genotyping was performed to identify blocks of homozygosity, identical-by-descent, wherein the disease locus would reside. COL11A1 was not within a region of homozygosity, further excluding it as the disease locus, but the gene encoding the proα2(XI) chain of type XI collagen, COL11A2, was located within a large region of homozygosity. Sequence analysis identified homozygosity for a splice donor mutation in intron 18. Exon trapping demonstrated that the mutation resulted in skipping of exon 18 and predicted deletion of 18 amino acids from the triple helical domain of the protein. In the second case, heterozygosity for a de novo 9 bp deletion in exon 40 of COL11A2 was identified, indicating that there are autosomal dominant forms of fibrochondrogenesis. These findings thus demonstrate that fibrochondrogenesis can result from either recessively- or dominantly-inherited mutations in COL11A2.

Hearing loss is the most prevalent sensory perception deficit in humans, affecting 1/500 newborns, can be syndromic or nonsyndromic and is genetically heterogeneous. Nearly 80% of inherited nonsyndromic bilateral sensorineural hearing loss (NBSNHI) is autosomal recessive. Although many causal genes have been identified, most are minor contributors, except for GJB2, which accounts for nearly 50% of all recessive cases of severe to profound congenital NBSNHI in some populations. More than 60% of children with a NBSNHI do not have an identifiable genetic cause. To identify genetic contributors, we genotyped 659 GJB2 mutation negative pediatric probands with NBSNHI and assayed for copy number variants (CNVs). After identifying 8 mild-moderate NBSNHI probands with a Chr15q15.3 deletion encompassing the Stereocilin (STRC) gene amongst this cohort, sequencing of STRC was undertaken in these probands as well as 50 probands and 14 siblings with mild-moderate NBSNHI and 40 probands with moderately severe-profound NBSNHI who were GJB2 mutation negative. The existence of a STRC pseudogene that is 99.6% homologous to the STRC coding region has made the sequencing interpretation complicated. We identified 7/50 probands in the mild-moderate cohort to have biallelic alterations in STRC, not including the 8 previously identified deletions. We also identified 2/40 probands to have biallelic alterations in the moderately severe-profound NBSNHI cohort, notably no large deletions in combination with another variant were found in this cohort. The data suggest that STRC may be a common contributor to NBSNHI among GJB2 mutation negative probands, especially in those with mild to moderate hearing impairment.

Cornelia de Lange syndrome (CdLS) is a congenital disorder characterized by distinctive facial features, growth retardation, limb abnormalities, intellectual disability, and behavioral problems. Autism has been reported to occur frequently in CdLS, but the frequency of autism in individuals with the milder CdLS phenotype is not well studied. We investigated autistic features by using a screening tool and a diagnostic interview in 49 individuals with the mild to moderate phenotype from a CdLS research database at the Children’s Hospital of Philadelphia. The Social Communication Questionnaire (SCQ), a screening instrument for autistic disorder, was completed for all individuals. For individuals who screened positive and a subset of those that screened negative, the Autism Diagnostic Interview-Revised (ADI-R) was administered. Autistic symptom severity was not significantly different by gender, age groups, and genotypes. There was a significant correlation between higher levels of adaptive functioning and lower scores of autistic symptoms. The estimated prevalence of significant autistic features by ADI-R criteria was 43% in our cohort of individuals with the mild to moderate CdLS phenotype, which suggests that prevalence of autistic disorder may be higher than previously described among individuals with mild to moderate phenotype of CdLS. Clinicians who take care of individuals with CdLS should have a high index of suspicion for autistic features, and refer for further evaluation when these features are present in order to expedite appropriate intervention.

Congenital heart disease (CHD) has been reported to occur in 14–70% of individuals with Cornelia de Lange syndrome (CdLS, OMIM 122470) and accounts for significant morbidity and mortality when present. Charts from a cohort of 479 patients with CdLS were reviewed for cardiac evaluations, gene testing and information to determine phenotypic severity. Two hundred fifty-nine individuals had either documented structural defects or minor cardiac findings. The presence of CHD was then quantified as a function of mutation status and severity of CdLS: mild, moderate, or severe. Different types of CHD were also evaluated by mutation status to assess for any genotype –phenotype correlation. NIPBL, SMC1A, and SMC3 mutation-positive patients were equally likely to have CHD, although the number of SMC1A and SMC3 mutation-positive patients were small in comparison. Structural CHDs were more likely to be present in individuals with moderate and severe CdLS than in the mild phenotype. This study evaluates the trends of CHD seen in the CdLS population and correlates these findings with genotype.

Women who participate in BRCA1/2 cancer genetic counseling do so for a variety of reasons, including learning quantitative risk information about their chances of developing hereditary breast-ovarian cancer at some point during their lifetimes. For these women, obtaining pre-test and disclosure genetic counseling with a professional affords them numerous potential benefits, including adequate preparation for, and accurate interpretation of, their test results. In consequence, women commonly report being highly satisfied with their cancer genetic counseling experience, even if the information learned through testing suggests they are at increased cancer risk. This occurrence raises an interesting question, namely what are the psychological aspects of satisfaction with genetic counseling for hereditary breast-ovarian cancer in women? To answer this question, we administered the Genetic Counseling Satisfaction Scale (GCSS) to a convenience sample of 61 women participating in BRCA1/2 pre-test genetic counseling, and re-administered the GCSS to approximately one-third of these women at disclosure. Available psychological data included personality, distress, and family functioning. In bivariate analyses, optimism and family functioning were positively associated with pre-test satisfaction. With respect to satisfaction at disclosure, general and cancer-specific distress were negatively associated with satisfaction. Our findings suggest that psychological aspects of satisfaction with cancer genetic counseling vary, with individual differences and family functioning playing a role at pre-test, and distress playing a role at disclosure. The implications for future research and clinical practice are discussed.

Neurofibromatosis type 2 (NF2) is a tumor suppressor syndrome characterized by bilateral vestibular schwannomas (VS) which often result in deafness despite aggressive management. Meningiomas, ependymomas and other cranial nerve and peripheral schwannomas are also commonly found in NF2 and collectively lead to major neurologic morbidity and mortality. Traditionally, the overall survival rate in patients with NF2 is estimated to be 38% at 20 years from diagnosis. Hence, there is a desperate need for new, effective therapies. Recent progress in understanding the molecular basis of NF2 related tumors has aided in the identification of potential therapeutic targets and emerging clinical therapies. In June 2010, representatives of the international NF2 research and clinical community convened under the leadership of Drs. D. Gareth Evans (University of Manchester) and Marco Giovannini (House Research Institute) to review the state of NF2 treatment and clinical trials. This manuscript summarizes the expert opinions about current treatments for NF2 associated tumors and recommendations for advancing therapies emerging from that meeting. The development of effective therapies for NF2 associated tumors has the potential for significant clinical advancement not only for patients with NF2 but for thousands of neuro-oncology patients afflicted with these tumors.

Disruptions in FOXP2, a transcription factor, are the only known monogenic cause of speech and language impairment. We report clinical findings for two new individuals with a submicroscopic deletion of FOXP2: a boy with severe apraxia of speech and his currently moderately affected mother. A 1.57 Mb deletion on chromosome 7q31 was detected by array Comparative Genomic Hybridization (aCGH). In addition to FOXP2, the patients’ deletion involves two other genes, MDFIC and PPP1R3A, neither of which has been associated with speech or language disorders. Thus, findings for these two family members provide informative phenotypic information on FOXP2 haploinsufficiency. Evaluation by a clinical geneticist indicated no major congenital anomalies or dysmorphic features. Evaluations by a clinical psychologist and occupational therapist indicated cognitive-linguistic processing and sensorimotor control deficits, but did not support a diagnosis of autism spectrum disorder. Evaluation by clinical and research speech pathologists confirmed that both patients’ speech deficits met contemporary criteria for apraxia of speech. Notably, the patients were not able to laugh, cough, or sneeze spontaneously, replicating findings reported for two other FOXP2 cases and a potential diagnostic sign of nonsyndromic apraxia of speech. Speech severity findings for the boy were not consistent with the hypothesis that loss of maternal FOXP2 should be relatively benign. Better understanding of the behavioral phenotype of FOXP2 disruptions will aid identification of patients, toward an eventual understanding of the pathophysiology of syndromic and nonsyndromic apraxia of speech.

Timothy syndrome (TS) is described as an autosomal dominant condition with the constellation of features including prolonged QT interval, hand and foot abnormalities and mental retardation or autism. Splawski et al. [2004] previously described two phenotypes associated with TS distinguished by two unique and different mutations within the CACNA1C gene. We report on a newborn who presented with prolonged QT interval and associated polymorphic ventricular tachycardia, dysmorphic facial features, syndactyly of the hands and feet and joint contractures, suggestive of TS. He developed a stroke, subsequent intractable seizures and was found to have cortical blindness and later profound developmental delay. Initial targeted mutation analysis did not identify either of the previously described TS associated mutations; however, full gene sequencing detected a novel CACNA1C gene mutation (p.Ala1473Gly). The clinical and genetic findings in our case expand both the clinical and molecular knowledge of TS.

Microtia is a congenital anomaly of the ear that ranges in severity from mild structural abnormalities to complete absence of the ear, and can occur as an isolated birth defect or as part of a spectrum of anomalies or a syndrome. Microtia is often associated with hearing loss and patients typically require treatment for hearing impairment and surgical ear reconstruction. The reported prevalence varies among regions, from 0.83 to 17.4 per 10,000 births and the prevalence is considered to be higher in Hispanics, Asians, Native Americans, and Andeans. The etiology of microtia and the cause of this wide variability in prevalence are poorly understood. Strong evidence supports the role of environmental and genetic causes for microtia. Although some studies have identified candidate genetic variants for microtia, no causal genetic mutation has been confirmed. The application of novel strategies in developmental biology and genetics has facilitated elucidation of mechanisms controlling craniofacial development. In this paper we review current knowledge of the epidemiology and genetics of microtia, including potential candidate genes supported by evidence from human syndromes and animal models. We also discuss the possible etiopathogenesis in light of the hypotheses formulated to date: neural crest cells disturbance, vascular disruption and altitude.

SUMMARY

The low-density lipoprotein (LDL) receptor family is a large evolutionarily conserved group of transmembrane proteins. It has been shown that LDL receptor family members can also function as direct signal transducers or modulators for a broad range of cellular signalling pathways. We have identified a novel mode of signalling pathway integration/coordination that occurs outside cells during development that involves an LDL family member. Physical interaction between an extracellular protein (Wise) that binds BMP ligands and an Lrp receptor (Lrp4) that modulates Wnt signalling, acts to link these two pathways. Mutations in either Wise or Lrp4 in mice produce multiple, but identical abnormalities in tooth development that are linked to alterations in BMP and Wnt signalling. Teeth, in common with many other organs, develop by a series of epithelial - mesenchymal interactions, orchestrated by multiple cell signalling pathways. In tooth development, Lrp4 is expressed exclusively in epithelial cells and Wise mainly in mesenchymal cells. Our hypothesis, based on the mutant phenotypes, cell signalling activity changes and biochemical interactions between Wise and Lrp4 proteins, is that Wise and Lrp4 together act as an extracellular mechanism of coordinating BMP and Wnt signalling activities in epithelial-mesenchymal cell communication during development.

We report nine new individuals from six families who have homozygous mutations of HOXA1 with either the Bosley-Salih-Alorainy Syndrome (BSAS) or the Athabascan Brainstem Dysgenesis Syndrome (ABDS). Congenital heart disease was present in four BSAS patients, two of whom had neither deafness nor horizontal gaze restriction. Two ABDS probands had relatively mild mental retardation. These individuals blur the clinical distinctions between the BSAS and ABDS HOXA1 variants and broaden the phenotype and genotype of the homozygous HOXA1 mutation clinical spectrum.

Although US research regulations allow for de-identified biorepositories to be developed without formal informed consent from the patients whose samples are included, it is unknown whether this model will be well-received by community members. Based on early evidence that such a biobank could be successful if patients who object have the opportunity to opt-out, Vanderbilt University developed a biorepository named BioVU that follows this model. This study reports the findings from two large-scale surveys among communities important to this biorepository. In the first, a population-based phone survey of Nashville residents, we found that approval for BioVU is high (93.9%) and that this approval is similar among all population groups. A hypothetical biobank that does not obtain some form of written permission is much less well received. In the second, an online survey of Vanderbilt University faculty and staff, we found a higher level of support for BioVU (94.5%) among faculty and staff working throughout the university. In this survey, employees least likely to approve of BioVU are those employees who prefer not to receive medical care at Vanderbilt University. These surveys demonstrate the highest level of approval for a genomic biobank ever reported in the literature, even among groups traditionally cautious about such research. This high level of approval may reflect increasing comfort with genomic research over time combined with the effect that trust in a specific institution can have on approval for an operating biobank compared with approval of a hypothetical biobank.

Angelman syndrome (AS) is due to deficient ubiquitin protein ligase 3a, the gene for which (UBE3A) maps to chromosome 15q11–q13 and is imprinted such that only the maternally inherited gene is expressed. The paternally inherited UBE3A gene is silenced, a process mediated by an antisense transcript. We conducted a trial using methylation-promoting dietary supplements (betaine, Metafolin, creatine and vitamin B12) in an attempt to reduce antisense transcript production, increase UBE3A expression and ameliorate the symptoms of AS. Neuropsychological evaluations, biochemical testing, and assessment of DNA methylation were performed at the beginning and at the end of one year of supplementation. The primary outcome measures were changes in the level of developmental function (cognitive, motor, and language) as measured using standardized instruments. The secondary outcomes measures were changes in biochemical parameters and global DNA methylation. These data were compared to those of a control group from a previous randomized double-blind trial using folic acid and betaine. There were no statistically significant changes in the developmental performance of children treated with supplements. There were no unexpected changes in biochemical parameters and no change in site-specific DNA methylation when comparing samples from before and after treatment. There were 10 adverse events that resulted in study withdrawal of 7 participants (worsening of seizures, onset or worsening of sleep problems, constipation, and anorexia). Supplementation with betaine, Metafolin, creatine and vitamin B12 appears safe but ineffective in decreasing the severity of AS.

To identify causes of death (COD) in propositi with Cornelia de Lange syndrome (CdLS) at various ages, and to develop guidelines to improve management and avoid morbidity and mortality, we retrospectively reviewed a total of 426 propositi with confirmed clinical diagnoses of CdLS in our database who died in a 41-year period between 1966–2007. Of these, 295 had an identifiable COD reported to us. Clinical, laboratory and complete autopsy data were completed on 41, of which 38 were obtainable, an additional 19 had autopsies that only documented the COD, and 45 propositi had surgical, imaging, or terminal event clinical documentation of their COD. Proband ages ranged from fetuses (21 to 40 weeks gestation) to 61 years. A literature review was undertaken to identify all reported causes of death in CdLS individuals.

In our cohort of 295 propositi with a known COD, respiratory causes including aspiration/reflux and pneumonias were the most common primary causes (31%), followed by gastrointestinal disease, including obstruction/volvulus (19%). Congenital anomalies accounted for 15% of deaths and included congenital diaphragmatic hernia and congenital heart defects. Acquired cardiac disease accounted for 3% of deaths. Neurological causes and accidents each accounted for 8%, sepsis for 4%, cancer for 2%, renal disease for 1.7%, and other causes, 9% of deaths. We also present 21 representative clinical cases for illustration.

This comprehensive review has identified important etiologies contributing to the morbidity and mortality in this population that will provide for an improved understanding of clinical complications, and management for children and adults with CdLS.

Individual studies of the genetics of neural tube defects (NTDs) contain results on a small number of genes in each report. To identify genetic risk factors for NTDs, we evaluated potentially functional single nucleotide polymorphisms (SNPs) that are biologically plausible risk factors for NTDs but that have never been investigated for an association with NTDs, examined SNPs that previously showed no association with NTDs in published studies, and tried to confirm previously reported associations in folate-related and non-folate-related genes. We investigated 64 SNPs in 34 genes for association with spina bifida in up to 558 case-families (520 cases, 507 mothers, 457 fathers) and 994 controls in Ireland. Case-control and mother-control comparisons of genotype frequencies, tests of transmission disequilibrium, and log-linear regression models were used to calculate effect estimates. Spina bifida was associated with over-transmission of the LEPR (leptin receptor) rs1805134 minor C allele (genotype relative risk (GRR): 1.5; 95% confidence interval (CI): 1.0, 2.1; P = 0.0264) and the COMT (catechol-O-methyltransferase) rs737865 major T allele (GRR: 1.4; 95% CI: 1.1, 2.0; P = 0.0206). After correcting for multiple comparisons, these individual test P-values exceeded 0.05. Consistent with previous reports, spina bifida was associated with MTHFR 677C>T, T (Brachyury) rs3127334, LEPR K109R, and PDGFRA promoter haplotype combinations. The associations between LEPR SNPs and spina bifida suggest a possible mechanism for the finding that obesity is a NTD risk factor. The association between a variant in COMT and spina bifida implicates methylation and epigenetics in NTDs.

Smith-Lemli-Opitz syndrome (SLOS) is a multiple malformation syndrome due to mutations of the 7-dehydrocholesterol reductase gene (DHCR7), which leads to a deficiency of cholesterol synthesis and an accumulation of 7-dehydrocholesterol and related metabolites. The SLOS clinical spectrum ranges from multiple major malformations to a mild phenotype with dysmorphic features, intellectual disability and a specific behavioral presentation. Several cases of SLOS with adrenal insufficiency have been described. We performed ovine corticotropin (oCRH) testing in 35 SLOS patients and 16 age- and gender-matched controls. We reviewed prior ACTH stimulation tests of our SLOS patients (19 of 35 available) and reviewed ACTH stimulation tests from additional 10 other SLOS patients. Results from oCRH testing showed that patients with SLOS had significantly higher ACTH baseline values than healthy controls (24.8 ± 15.3 pg/mL vs. 17.8 ± 7.5 pg/mL, p=0.034). However, no statistically significant differences were noted for peak ACTH values (74.4 ± 35.0 pg/mL vs. 64.0 ± 24.9 pg/mL, p=0.303) and for baseline (14.2 ± 7.8 mcg/dL vs. 14.2 ± 6.3 mcg/dL, p=0.992) and peak cortisol values (28.2 ± 7.9 mcg/dL vs. 24.8 ± 8.1 mcg/dL, p=0.156). The area-under-the-curve (AUC) was not significantly different in SLOS patients compared to controls for both ACTH (250.1 ± 118.7 pg/mL vs. 195.3 ± 96.6 pg/mL, p=0.121) as well as cortisol secretion (83.1 ± 26.1 mcg/dL vs. 77.8 ± 25.9 mcg/dL, p=0.499). ACTH stimulation test was normal in 28 of 29 tests. The individual with the abnormal ACTH stimulation test had a normal oCRH test during the same evaluation. The slightly increased baseline ACTH level seen during oCRH testing may be due to compensated mild adrenocortical insufficiency. However, we were able to show that our cohort affected with SLOS had an adequate stress response and that in mild to moderate cases of SLOS stress steroid coverage should not be required.

Trisomy 21, the chromosomal condition responsible for Down syndrome (DS, OMIM #190685), is the most common identifiable genetic cause of intellectual disability. Approximately half of all children with DS are born with a significant congenital heart defect (CHD), the most common of which is an atrioventricular septal defect (AVSD). As children with comorbid DS and CHD increasingly survive cardiac surgery, characterization of their early developmental trajectories is critical for designing early interventions to maximize individual potential. Herein, the developmental domains (cognitive, language, and motor) of children with DS and AVSD (DS + AVSD, n=12) were compared to children with DS and a structurally normal heart (DS – CHD, n=17) using the Bayley Scales of Infant and Toddler Development III. The DS + AVSD cohort mean age was relatively the same as controls with DS – CHD, 14.5 ±7.3 months compared with 14.1 ± 8.4 months, respectively. Although the motor domain was the only domain that showed a statistically significant difference between groups (p < .05), both cognitive standard scores (p = 0.63) and language composite standard scores (p = 0.10) were lower in the DS + AVSD cases compared with the DS – CHD controls although it is not statistically significant. Since this is the first study to examine the early developmental outcomes of children with DS + AVSD, the findings may be useful for clinicians in providing anticipatory guidance.