Autosomal recessive woolly hair and hypotrichosis (ARWH) is a rare form of congenital alopecia characterized by sparse hair on the scalp, and it sometimes expands to all the body hair. ARWH is known to be caused by mutations in LIPH or LPAR6.1,2 Recently, Zernov et al. reported that the KRT25 gene causes autosomal-recessive hypotrichosis with woolly hair.3 LIPH encodes a membrane-bound member of the mammalian triglyceride lipase family, lipase H.1 LPAR6 encoded by LPAR6 and LIPH are both involved in the same pathway of regulation of hair differentiation and growth.1,2 To date, 24 pathogenic mutations in LIPH have been reported in ARWH (w w w . hgmd. cf .ac .uk, as of HGMD professional, 2016.1). They comprise 9 missense/nonsense, 2 splice-site, 5 small-deletion, 2 small-insertion, 3 small-indel, 2 gross-deletion and 1 gross-insertion mutations. Of these, the 2 mutations c.736T>A and c.742C>A in LIPH have been reported as extremely prevalent causative mutations for ARWH in the Japanese population. We confirmed the high frequencies of the 2 founder mutations, especially of c.736T>A, in 819 Japanese controls.4 The LIPH mutations c.736T>A (p.Cys246Ser) and c.742C>A (p.His248Asn) were proven to be dysfunctional by in vitro studies.5 Precisely how often these two founder mutations in LIPH are seen in Japanese ARWH patients remains uncertain. This article is protected by copyright. All rights reserved.