The Ashkenazi Jewish Fanconi anemia mutation: Incidence among patients and carrier frequency in the at‐risk population

Fanconi anemia (FA) is an autosomal recessive disease for which at least four complementation groups exist. Recently the gene that corrects the defect in Fanconi anemia complementation group C cells (FACC) has been cloned. We have previously identified a common mutation in the FACC gene, which accounts for a majority of FA cases in Ashkenazi Jewish individuals. We here describe the use of allele‐specific oligonucleotide (ASO) hybridization to determine the frequency of this mutation among additional Jewish FA patients and to determine the carrier frequency in the Jewish population. The common IVS4 + 4A → T allele was found on 19/23 (83%) Jewish FA chromosomes, indicating that it is indeed responsible for most cases of FA among Ashkenazi Jews. The carrier frequency was 2/314 for Jewish individuals and the mutant allele was not detected in 130 non‐Jewish controls. © 1994 Wiley‐Liss, Inc.