Familial posterior labial fusion

Partial virilization at birth of a genotypic female resulting in varying degrees of posterior labial fusion and clitoral enlargement is most commonly due to excess androgen production from congenital adrenal hyperplasia. Rarely, labial fusion arises secondary to maternal androgen ingestion or an androgen-secreting tumor during pregnancy. We report a case of posterior labial fusion without clitorimegaly in a 12-year-old girl in which there was no evidence of androgen excess. The family history was remarkable for a similar congenital defect in two aunts and their daughters, suggesting an autosomal dominant trait with incomplete penetrance.