Hypertrichosis is defined as hair growth that is excessive for a particular site of the body or age of the patient and that is not hormone-dependent (summary by Fantauzzo et al., 2012). Genetic Heterogeneity of Congenital Generalized Hypertrichosis HTC1 has been mapped to chromosome 8q. HTC2 (307150) is caused by palindrome-mediated interchromosomal insertion at chromosome Xq27. HTC3 (135400), which can occur with or without associated gingival hyperplasia, is caused by deletion or duplication at chromosome 17q24 or by mutation in the ABCA5 gene (612503) on chromosome 17q24. Also see lanugo-like generalized congenital hypertrichosis (145700). [from OMIM]