Isolated autosomal recessive wavy hair/hypotrichosis (ARWH) is a rare congenital disorder in which the hair is sparse and tightly coiled. The cause is mutations in the LIPH, LPAR6/P2RY5, KRT25 and C3ORF52 genes, with the LIPH and LPAR6 genes being most often affected. The prevalence of mutations varies by region: in Japan, c.736T>A and c.742C>A mutations in LIPH are frequent, in Pakistan there is a recurrent deletion of LIPH exon 5 (c.659660del), in Russia a deletion of exon 4 (c.527628del), and 12 of 19 Chinese cases have a LIPH c.742C>A mutation. LPAR6 mutations are rare, occurring mainly in Pakistan and China. KRT25 mutations include Russian variant c.712G>T and Pakistani c.950T>C, C3ORF52 mutations are new and reported in only two cases in the US. There is no definitive treatment, but minoxidil, gentamicin, regenerative therapies, and herbal compounds show some potential. Mutation patterns show genetic founder influence and regional differences in ARWH pathogenesis.