Familial dysautonomia: detection of the IKBKAP IVS20(+6T --> C) and R696P mutations and frequencies among Ashkenazi Jews.
Familial dysautonomia (FD) is an autosomal recessive congenital neuropathy that occurs almost exclusively in the Ashkenazi Jewish (AJ) population. Mutations in the IkappaB kinase complex-associated protein (IKBKAP) gene cause FD. Two IKBKAP mutations, IVS20(+6T --> C) and R696P, have been identified in FD patients of AJ descent. The splice site mutation IVS20(+6T --> C) is responsible for > 99.5% of known AJ patients with FD, and haplotype analyses were consistent with a common founder. In contrast, the R696P mutation has been identified in only a few AJ patients. To facilitate carrier detection, a single PCR and allele-specific oligonucleotide (ASO) hybridization assay was developed to facilitate the detection of both the IVS20(+6T --> C) and R696P mutations. Screening of 2,518 anonymous AJ individuals from the New York metropolitan area revealed a carrier frequency for IVS20(+6T --> C) of 1 in 32 (3.2%; 95% CI, 2.5-3.9%), similar to the previously estimated carrier frequency (3.3%) based on disease incidence. No carrier was identified for the R696P lesion, indicating that the mutation was rare in this population (< 1 in 2,500). This sensitive and specific assay should facilitate carrier screening for FD mutations in the AJ community, as well as postnatal diagnostic testing.
Department of Human Genetics, Mount Sinai School of Medicine of New York University, New York, New York 10029, USA.
Jianli
J
Dong
Lisa
L
Edelmann
Asghar M
AM
Bajwa
Ruth
R
Kornreich
Robert J
RJ
Desnick
D017398:Alternative Splicing / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics*; D004247:DNA / Q000235:genetics; D004402:Dysautonomia, Familial / Q000453:epidemiology / Q000235:genetics*; D005787:Gene Frequency; D005820:Genetic Testing; D006579:Heterozygote; D007585:Jews / Q000235:genetics*; D009154:Mutation; D020125:Mutation, Missense; D009518:New York / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D035602:Transcriptional Elongation Factors
D002352:Carrier Proteins; C114720:Elp1 protein, human; D035602:Transcriptional Elongation Factors; D004247:DNA