is a variant in the RECQL3
gene causing Bloom syndrome
, and this particular SNP accounts for >95% of such cases in the Ashkenazi
population. Note that this variation is somewhat complex, in that it represents a deletion of 6 bases along with an insertion of 7 bases at the same site. The terminology used in dbSNP (and here in SNPedia) indicates the normal allele as having the six bases ATCTGA, whereas the abnormal allele is shown only as a deletion of these six bases, without indicating the insertion. See also OMIM 604610.0001
23andMe name: i4000396 However, note that the (D;D) genotype represents the normal genotype as reported for this i-SNP (contrary to convention)
[PMID 9837821] The Ashkenazic Jewish Bloom syndrome mutation blmAsh is present in non-Jewish Americans of Spanish ancestry.