title: The Ashkenazic Jewish Bloom syndrome mutation blmAsh is present in non-Jewish Americans of Spanish ancestry.
abstract: Bloom syndrome (BS) is more frequent in the Ashkenazic Jewish population than in any other. There the predominant mutation, referred to as "blmAsh," is a 6-bp deletion and 7-bp insertion at nucleotide position 2281 in the BLM cDNA. Using a convenient PCR assay, we have identified blmAsh on 58 of 60 chromosomes transmitted by Ashkenazic parents to persons with BS. In contrast, in 91 unrelated non-Ashkenazic persons with BS whom we examined, blmAsh was identified only in 5, these coming from Spanish-speaking Christian families from the southwestern United States, Mexico, or El Salvador. These data, along with haplotype analyses, show that blmAsh was independently established through a founder effect in Ashkenazic Jews and in immigrants to formerly Spanish colonies. This striking observation underscores the complexity of Jewish history and demonstrates the importance of migration and genetic drift in the formation of human populations.
authors.affiliation: Department of Human Genetics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, USA. n-ellis@ski.mskcc.org
authors.forename: N A
authors.initials: NA
authors.lastname: Ellis
authors.forename: S
authors.initials: S
authors.lastname: Ciocci
authors.forename: M
authors.initials: M
authors.lastname: Proytcheva
authors.forename: D
authors.initials: D
authors.lastname: Lennon
authors.forename: J
authors.initials: J
authors.lastname: Groden
authors.forename: J
authors.initials: J
authors.lastname: German
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics*; D000483:Alleles; D001816:Bloom Syndrome / Q000208:ethnology / Q000235:genetics*; D002835:Christianity; D002877:Chromosomes, Human; D003241:Consanguinity; D004265:DNA Helicases / Q000235:genetics*; D004544:El Salvador; D018703:Founder Effect; D005787:Gene Frequency; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007585:Jews / Q000235:genetics*; D008800:Mexico; D009154:Mutation; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D053484:RecQ Helicases; D013030:Spain / Q000208:ethnology; D014481:United States
chemical_list: D000251:Adenosine Triphosphatases; C097151:Bloom syndrome protein; D004265:DNA Helicases; D053484:RecQ Helicases