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1.  Clinical Characterization of a Kindred with a Novel Twelve Octapeptide Repeat Insertion in the Prion Protein Gene 
Archives of Neurology  2011;68(9):1165-1170.
To report the clinical, electroencephalographic, and neuroradiologic findings in a kindred with a novel insertion in the prion protein gene (PRNP).
Clinical description of a kindred.
Mayo Clinic Alzheimer’s Disease Research Center (Rochester).
Two pathologically-confirmed cases and their relatives.
Main outcome measures
Clinical features, electroencephalographic patterns, magnetic resonance imaging abnormalities, genetic analyses and neuropathological features.
The proband presented with clinical and neuroimaging features of atypical frontotemporal dementia (FTD) and ataxia. Generalized tonic-clonic seizures developed later in her course, and electroencephalography revealed spike and wave discharges but no periodic sharp wave complexes. Her affected sister and father also exhibited FTD-like features, and both experienced generalized tonic-clonic seizures and gait ataxia late in their course. Genetic analyses in the proband identified a novel defect in PRNP with one mutated allele carrying a 288 base pair insertion (BPI) consisting of 12 octapeptide repeats. Neuropathologic examination of the sister and proband revealed PrP-positive plaques and widespread tau-positive tangles.
This kindred has a unique combination of clinical and neuropathologic features associated with the largest BPI identified to date in PRNP, and underscores the need to consider familial prion disease in the differential diagnosis of a familial FTD-like syndrome.
PMCID: PMC3326586  PMID: 21911696
frontotemporal dementia; FTD; nonfluent aphasia; Gerstmann–Straüssler–Scheinker syndrome (GSS); Creutzfeldt-Jakob disease (CJD); prion; PRNP
2.  A Non-classical Presentation of Tangier Disease with Three ABCA1 Mutations 
JIMD Reports  2011;4:109-111.
Tangier disease is a very rare autosomal recessive inherited disorder characterized by markedly reduced high-density lipoprotein (HDL) levels, characteristic large, yellow–orange tonsils, and enlarged liver, spleen and lymph nodes. It is caused by mutations in the ABCA1 gene. There is no specific treatment, and medications traditionally used to increase HDL are ineffective. A number of patients with non-classical Tangier disease have been described in the literature, who presented with low HDL levels, corneal lesions, hepatosplenomegaly, and thrombocytopenia. We report here about a 45-year-old female with a past medical history of early coronary artery disease, myocardial infarction, multiple episodes of angina, immeasurable HDL, and a history of idiopathic thrombocytopenia purpura. She had a tonsillectomy performed previously, but did not remember if the tonsils were of any unusual color. There was no history of peripheral neuropathy. Her family history is significant for her father and mother having Alzheimer disease and hypertension, respectively. On physical examination she did not have any hepatosplenomegaly or corneal opacities. She was found to have three mutations in the ABCA1 gene. These were designated A1046D (c.3137C>A) in exon 22; Y1532C (c.4595A>G) in exon 34, and W1699C (c.5097G>T) in exon 37. All three have been reported to be deleterious in functional studies. The patient has immeasurable HDL, which leads us to assume that two mutations are on one allele and one mutation on the other. We suspect that this condition is under-diagnosed, and as more patients are reported in the literature, the phenotype of Tangier disease will be elucidated further.
PMCID: PMC3509900  PMID: 23430904
3.  Characterization of New ACADSB Gene Sequence Mutations and Clinical Implications in Patients with 2-Methylbutyrylglycinuria Identified by Newborn Screening 
Molecular genetics and metabolism  2010;100(4):333-338.
Short/branched chain acyl-CoA dehydrogenase (SBCAD) deficiency, also known as 2-methylbutyryl-CoA dehydrogenase deficiency, is a recently described autosomal recessive disorder of isoleucine metabolism. Most patients reported thus far have originated from a founder mutation in the Hmong Chinese population. While the first reported patients had severe disease, most of the affected Hmong have remained asymptomatic. In this study we describe 11 asymptomatic non-Hmong patients brought to medical attention by elevated C5-carnitine found by newborn screening and one discovered because of clinical symptoms. The diagnosis of SBCAD deficiency was determined by metabolite analysis of blood, urine, and fibroblast samples. PCR and bidirectional sequencing were performed on genomic DNA from five of the patients covering the entire SBCAD (ACADSB) gene sequence of 11 exons. Sequence analysis of genomic DNA from each patient identified variations in the SBCAD gene not previously reported. E. coli expression studies revealed that the missense mutations identified lead to inactivation or instability of the mutant SBCAD enzymes. These findings confirm that SBCAD deficiency can be identified through newborn screening by acylcarnitine analysis. Our patients have been well without treatment and call for careful follow-up studies to learn the true clinical impact of this disorder.
PMCID: PMC2906669  PMID: 20547083
Branched Chain Acyl Coenzyme A Dehydrogenase; 2-Methylbutyryl Coenzyme A dehydrogenase; organic acidemia; isoleucine metabolism; acyl-CoA dehydrogenase; newborn screening
4.  Zoom‐in comparative genomic hybridisation arrays for the characterisation of variable breakpoint contiguous gene syndromes 
Journal of Medical Genetics  2007;44(1):e59.
Contiguous gene syndromes cause disorders via haploinsufficiency for adjacent genes. Some contiguous gene syndromes (CGS) have stereotypical breakpoints, but others have variable breakpoints. In CGS that have variable breakpoints, the extent of the deletions may be correlated with severity. The Greig cephalopolysyndactyly contiguous gene syndrome (GCPS‐CGS) is a multiple malformation syndrome caused by haploinsufficiency of GLI3 and adjacent genes. In addition, non‐CGS GCPS can be caused by deletions or duplications in GLI3. Although fluorescence in situ hybridisation (FISH) can identify large deletion mutations in patients with GCPS or GCPS‐CGS, it is not practical for identification of small intragenic deletions or insertions, and it is difficult to accurately characterise the extent of the large deletions using this technique. We have designed a custom comparative genomic hybridisation (CGH) array that allows identification of deletions and duplications at kilobase resolution in the vicinity of GLI3. The array averages one probe every 730 bp for a total of about 14 000 probes over 10 Mb. We have analysed 16 individuals with known or suspected deletions or duplications. In 15 of 16 individuals (14 deletions and 1 duplication), the array confirmed the prior results. In the remaining patient, the normal CGH array result was correct, and the prior assessment was a false positive quantitative polymerase chain reaction result. We conclude that high‐density CGH array analysis is more sensitive than FISH analysis for detecting deletions and provides clinically useful results on the extent of the deletion. We suggest that high‐density CGH array analysis should replace FISH analysis for assessment of deletions and duplications in patients with contiguous gene syndromes caused by variable deletions.
PMCID: PMC2597909  PMID: 17098889
GLI3 ; oligonucleotide array; comparative genomic hybridization
5.  Experience with microarray-based comparative genomic hybridization for prenatal diagnosis in over 5000 pregnancies 
Prenatal Diagnosis  2012;32(10):976-985.
To demonstrate the usefulness of microarray testing in prenatal diagnosis based on our laboratory experience.
Prenatal samples received from 2004 to 2011 for a variety of indications (n = 5003) were tested using comparative genomic hybridization-based microarrays targeted to known chromosomal syndromes with later versions of the microarrays providing backbone coverage of the entire genome.
The overall detection rate of clinically significant copy number alterations (CNAs) among unbiased, nondemise cases was 5.3%. Detection rates were 6.5% and 8.2% for cases referred with abnormal ultrasounds and fetal demise, respectively. The overall rate of findings with unclear clinical significance was 4.2% but would reduce to 0.39% if only de novo CNAs were considered. In cases with known chromosomal rearrangements in the fetus or parent, 41.1% showed CNAs related to the rearrangements, whereas 1.3% showed clinically significant CNAs unrelated to the karyotype. Finally, 71% of the clinically significant CNAs found by microarray were below the resolution of conventional karyotyping of fetal chromosomes.
Microarray analysis has advantages over conventional cytogenetics, including the ability to more precisely characterize CNAs associated with abnormal karyotypes. Moreover, a significant proportion of cases studied by array will show a clinically significant CNA even with apparently normal karyotypes. © 2012 John Wiley & Sons, Ltd.
PMCID: PMC3491694  PMID: 22865506
6.  Detection rates of clinically significant genomic alterations by microarray analysis for specific anomalies detected by ultrasound 
Prenatal Diagnosis  2012;32(10):986-995.
The aim of this study is to understand the diagnostic utility of comparative genomic hybridization (CGH)-based microarrays for pregnancies with abnormal ultrasound findings.
We performed a retrospective analysis of 2858 pregnancies with abnormal ultrasounds and normal karyotypes (when performed) tested in our laboratory using CGH microarrays targeted to known chromosomal syndromes with later versions providing backbone coverage of the entire genome. Abnormalities were stratified according to organ system involvement. Detection rates for clinically significant findings among these categories were calculated.
Clinically significant genomic alterations were identified in cases with a single ultrasound anomaly (n = 99/1773, 5.6%), anomalies in two or more organ systems (n = 77/808, 9.5%), isolated growth abnormalities (n = 2/76, 2.6%), and soft markers (n = 2/77, 2.6%). The following anomalies in isolation or with additional anomalies had particularly high detection rates: holoprosencephaly (n = 9/85, 10.6%), posterior fossa defects (n = 21/144, 14.6%), skeletal anomalies (n = 15/140, 10.7%), ventricular septal defect (n = 14/132, 10.6%), hypoplastic left heart (n = 11/68, 16.2%), and cleft lip/palate (n = 14/136, 10.3%).
Microarray analysis identified clinically significant genomic alterations in 6.5% of cases with one or more abnormal ultrasound findings; the majority were below the resolution of karyotyping. Larger data sets such as this allow for sub-stratification by specific anomalies to determine risks for genomic alterations detectable by microarray analysis. © 2012 John Wiley & Sons, Ltd.
PMCID: PMC3509216  PMID: 22847778
abnormal ultrasound; microarray; Array CGH < PRENATAL CYTOGENETICS; prenatal; congenital anomalies; soft markers

Results 1-6 (6)