Familial hypotrichosis of the scalp. Autosomal dominant inheritance in four generations.

We describe a Danish family of four generations suffering from hypotrichosis of the scalp. Age at onset was 6-17 years and almost total scalp alopecia was reached by the age of 14-21 years. No associated ectodermal defects were present. Nine of 22 persons covering four generations were affected. Growth of the scalp hair slowly decreased and was accompanied by a gradual, diffuse hair loss without regional variation. A scalp biopsy was performed, revealing a non-scarring alopecia with features of androgenetic alopecia. The pedigree was compatible with autosomal dominant inheritance.