Aplasia cutis congenita in two siblings

We report on two siblings with aplasia cutis congenita (ACC). This rare congenital malformation is characterized by a local defect of epidermis, dermis, and subcutaneous tissues occurring predominantly on the vertex of the scalp. Patient A (a boy) was born with a parietooccipital 4 x 4 cm scalp defect, that healed under conservative treatment with scar formation within three months. At the age of three years we started with serial excisions of the affected area. In patient B (a girl) two 1.5 x 1.5 cm midline scalp defects were noted at birth. After primary conservative treatment we performed an excision at the age of three years. Both children were born at term following normal pregnancy and delivery. Neither physical nor psychomotor retardation nor any other associated abnormality was found in these cases. Two younger brothers were born without any skin defects or other anomalies. There is no unifying theory on the pathogenesis of ACC. Traumatic, vascular, teratogenic, and genetic factors are discussed as initial steps in etiopathogenesis. In this family the occurrence of ACC in two siblings of either sex, with unaffected parents, may suggest an autosomal recessive mode of transmission. However autosomal dominant inheritance with germline mosaicism in one parent can not be excluded.