Ataxia-telangiectasia and Swiss-type agammaglobulinemia. Two genetic disorders of the immune mechanism in related Amish sibships

Abstract

Two sibships, one with typical ataxia-telangiectasia (AT) and one with typical Swiss-type agammaglobulinemia (SAG), were observed in the Old Order Amish. Sibs of the patient with AT died early with a clinical picture consistent with SAG . Furthermore, the 4 patients of the 2 sibships share a common ancestral couple. The findings suggest, but do not prove, genetic identity of AT and one form of SAG. More conclusive evidence will be provided by well-studied sibships, preferably non-Amish, in which one or more sibs had SAG and other sibs had AT.