A novel mutation in the IHH gene causes brachydactyly type A1: a 95-year-old mystery resolved.

Brachydactyly type A1 (BDA1) was the first disorder described in terms of autosomal dominant Mendelian inheritance. Early in the 1900s Farabee and Drinkwater described a number of families with BDA1. Examination of two of Drinkwater's families has revealed that, although they are not known to be related, both share a common mutation within the Indian hedgehog gene ( IHH).