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Shevach E.,Hebrew University of Jerusalem | Ali M.,St Jamess Hospital | Mizrahi-Meissonnier L.,Hebrew University of Jerusalem | McKibbin M.,St Jamess Hospital | And 8 more authors.
JAMA Ophthalmology | Year: 2015

IMPORTANCE: A large number of genes can cause inherited retinal degenerations when mutated. It is important to identify the cause of disease for a better disease prognosis and a possible gene-specific therapeutic intervention. OBJECTIVE: To identify the cause of disease in families with nonsyndromic retinitis pigmentosa. DESIGN, SETTING, AND PARTICIPANTS: Patients and family members were recruited for the study and underwent clinical evaluation and genetic analyses. MAIN OUTCOMES AND MEASURES: Identification of sequence variants in genes using next-generation sequencing. RESULTS: We performed exome sequencing for 4 families, which was followed by Sanger sequencing of the identified mutations in 120 ethnicity-matched patients. In total, we identified 4 BBS2 missense mutations that cause nonsyndromic retinitis pigmentosa. Three siblings of Moroccan Jewish ancestry were compound heterozygotes for p.A33D and p.P134R, and 6 patients belonging to 4 families of Ashkenazi Jewish ancestry were homozygous for either p.D104A or p.R632P, or compound heterozygous for these 2 mutations. The mutations cosegregated with retinitis pigmentosa in the studied families, and the affected amino acid residues are evolutionarily conserved. CONCLUSIONS AND RELEVANCE: Our study shows that BBS2 mutations can cause nonsyndromic retinitis pigmentosa and highlights yet another candidate for this genetically heterogeneous condition. Copyright 2015 American Medical Association. All rights reserved. Source

Jalas C.,Center for Rare Jewish Genetic Disorders | Anderson S.L.,Fordham University | Laufer T.,Fordham University | Martimucci K.,Fordham University | And 4 more authors.
Blood Cells, Molecules, and Diseases | Year: 2011

Congenital amegakaryocytic thrombocytopenia (MIM #. 604498) (CAMT) is a rare inherited disease presenting as severe thrombocytopenia in infancy. Untreated, many CAMT patients develop aplastic anemia within the first decade of life; the only effective treatment of CAMT is bone marrow transplantation. CAMT is the result of the presence of homozygous or compound heterozygous mutations in the thrombopoietin receptor-encoding gene, MPL. We report here the identification and characterization of a founder mutation in MPL in the Ashkenazi Jewish (AJ) population. This mutation, termed c.79. +. 2T > A, is a T to A transversion in the invariant second base of the intron 1 donor splice site. Analysis of a random sample of 2018 individuals of AJ descent revealed a carrier frequency of approximately 1 in 75. Genotyping of six loci adjacent to the MPL gene in the proband and in the 27 individuals identified as carriers of the c.79. +. 2T > A mutation revealed that the presence of this mutation in the AJ population is due to a single founder. The observed carrier frequency predicts an incidence of CAMT in the AJ population of approximately 1 in 22,500 pregnancies. The identification of this mutation will enable population carrier testing and will facilitate the identification and treatment of individuals homozygous for this mutation. © 2011 Elsevier Inc. Source

Fedick A.,Johnson University | Jalas C.,Center for Rare Jewish Genetic Disorders | Treff N.R.,Johnson University
Clinical Genetics | Year: 2014

Zellweger syndrome is known to be caused by numerous mutations that occur in at least 12 of the PEX genes. While phenotypes vary, many are severely debilitating, and death can result in affected newborns. Since the disease follows an autosomal recessive pattern of inheritance, carrier screening can be done for at-risk couples, but the number of potential mutations sites to screen can be daunting. Ethnicity-specific studies can help narrow this range by highlighting mutations that are present at higher percentages in certain populations. In this article, the carrier frequencies for two mutations causative of the severe Zellweger syndrome spectrum phenotype that occur in the PEX2 gene, c.355C>T and c.550del, were studied in individuals of Ashkenazi Jewish descent in order to advise on inclusion in existing carrier screening mutation panels for this population. The screening was performed for 2093 individuals through the use of TaqMan genotyping assays, real-time PCR, and allelic discrimination. Results indicated a carrier frequency of 0.813% (±0.385%) for the c.355C>T mutation and a carrier frequency of 0.00% (±0.00%) for the c.550del mutation. On the basis of these frequencies, we believe that the c.355C>T mutation should be considered for inclusion in carrier screening panels for the Ashkenazi population. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. Source

Fedick A.,Johnson University | Su J.,Reproductive Medicine Associates of New Jersey | Jalas C.,Center for Rare Jewish Genetic Disorders | Northrop L.,Reproductive Medicine Associates of New Jersey | And 3 more authors.
PLoS ONE | Year: 2013

Members of the Ashkenazi Jewish community are at an increased risk for inheritance of numerous genetic diseases such that carrier screening is medically recommended. This paper describes the development and evaluation of 30 TaqMan allelic discrimination qPCR assays for 29 mutations on 2 different high-throughput platforms. Four of these mutations are in the GBA gene and are successfully examined using short amplicons due to the qualitative nature of TaqMan allelic discrimination. Two systems were tested for their reliability (call rate) and consistency with previous diagnoses (diagnostic accuracy) indicating a call rate of 99.04% and a diagnostic accuracy of 100% (+/-0.00%) from one platform, and a call rate of 94.66% and a diagnostic accuracy of 93.35% (+/-0.29%) from a second for 9,216 genotypes. Results for mutations tested at the expected carrier frequency indicated a call rate of 97.87% and a diagnostic accuracy of 99.96% (+/-0.05%). This study demonstrated the ability of a high throughput qPCR methodology to accurately and reliably genotype 29 mutations in parallel. The universally applicable nature of this technology provides an opportunity to increase the number of mutations that can be screened simultaneously, and reduce the cost and turnaround time for accommodating newly identified and clinically relevant mutations. © 2013 Fedick et al. Source

Edvardson S.,Hebrew University of Jerusalem | Cinnamon Y.,Hebrew University of Jerusalem | Jalas C.,Center for Rare Jewish Genetic Disorders | Shaag A.,Hebrew University of Jerusalem | And 3 more authors.
Annals of Neurology | Year: 2012

In 4 infants with a new lethal autonomic sensory neuropathy with clinical features similar to familial dysautonomia as well as contractures, we identified a deleterious mutation in the DST gene, using homozygosity mapping followed by exome sequencing. DST encodes dystonin, a cytoskeleton linker protein, and the mutation results in an unstable transcript. Interestingly, dystonin is significantly more abundant in cells of familial dysautonomia patients with IKBKAP (I-κ-B kinase complex-associated protein) mutation compared to fibroblasts of controls, suggesting that upregulation of dystonin is responsible for the milder course in familial dysautonomia. Homozygosity mapping followed by exome sequencing is a successful approach to identify mutated genes in rare monogenic disorders. Copyright © 2012 American Neurological Association. Source

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