An inherited metabolic disorder may be associated with alopecia or hair shaft abnormalities.
Alopecia associated with the metabolic disorder:
(1) holocarboxylase synthetase deficiency (with alopecia totalis)
(2) biotinidase deficiency
(3) porphyria
(4) vitamin D-resistant rickets Type II (involving the receptor for 1,25-hydroxycalciferol, with alopecia totalis)
Alopecia secondary to protein malnutrition caused by dietary restrictions:
(1) organic aciduries
(2) urea cycle disorders
Conditions with hair shaft abnormalities:
(1) arginine-succinic aciduria (with trichorrhexis nodosa)
(2) Menkes disease (with trichorrhexis nodosa, pili torti or monilethrix)