A large duplication in LIPH underlies autosomal recessive hypotrichosis simplex in four Middle Eastern families.

Autosomal recessive hypotrichosis simplex (ARHS) manifests with paucity of hair appearing during early childhood. We assessed four affected families. We initially genotyped three of these families for a panel of microsatellite markers spanning all ARHS-associated loci and obtained data suggesting linkage to 3q27, encompassing LIPH, which had previously been shown to be associated with ARHS. Accordingly, a homozygous duplication mutation in exon 2 of this gene (c.280_369dup; p.Gly94_Lys123dup) was found to segregate with the disease in all the families. Through the identification of the first duplication mutation in the human LIPH gene, we provide further evidence supporting a role for the phospholipase signalling pathway in hair growth and differentiation.