Focal dermal hypoplasia

Focal dermal hypoplasia in five sisters and their mother is presented. The lesions present in this family and in eight additional Mexican cases are reviewed. Fourteen out of 15 cases were females and two were males. All cases had cutaneous lesions, clinically typical of focal dermal hypoplasia; these were confirmed histologically. Osseous changes and syndactyly were the more frequently associated lesions. The resemblance of this syndrome to incontinentia pigmenti and to aplasia cutis congenita is stressed. The study of this family, together with five families reported in the literature, suggests X‐linked dominant inheritance with lethality in males. The known male cases could represent occasional survival or genetic heterogeneity.