[Type A1 branchydactyly. Study of one family (author's transl)].

Five members of a kindred with type A1 brachydactyly were ascertained. The middle phalanges of the last four fingers were short, rudimentary or absent, and the proximal phalanges of the thumbs and great toes were shortened. Emergence of the brachydactyly in the children of an unaffected woman suggested the possibility of a half chromatid mutation or of a premutation. The pedigree was then consistant with autosomal dominant inheritance with complete penetrance for brachydactyly.