Chromosome: 8p12
Gene mutated: hir (hairless gene)
Clinical findings:
(1) There is a family history of alopecia with an autosomal pattern of inheritance. There may be a history of consanguinity.
(2) Alopecia may be present at birth or develop during infancy. Once lost the hair never regrows.
(3) There is an absence of scalp hair, which may be complete or nearly complete (alopecia totalis).
(4) Eyebrows and eyelashes are sparse.
(5) After adolescence there is an absence of axillary, pubic and body hair (alopecia universalis).
(6) There are whitish hypopigmented streaks over the scalp.
(7) Papules (from few to many) may be noted over the scalp, cheeks, and extremities, starting during infancy.
(8) Failure of the alopecia to respond to any treatment.
(9) Absence of growth or developmental problems with normal nails, teeth and sweating.
Laboratory findings:
(1) A mutation in the hir gene may be noted.
(2) Skin biopsy shows an absence of mature hair follicles, with cysts containing cornified material.
