Mutations in lipase H cause autosomal recessive hypotrichosis simplex with woolly hair

Abstract

Mutations in lipase H (LIPH) are a rare cause of autosomal recessive hypotrichosis (HT) simplex. In this study, we investigated the clinical and molecular basis of HT simplex with woolly hair in 3 nonrelated families. Three families of Jewish, Arab Muslim, and Italian origin that presented with HT with woolly hair were studied. The phenotype was confirmed by clinical, microscopic, and histologic examination. Polymorphic microsatellite genotyping and direct automated DNA sequencing of the LIPH gene were used to identify the mutations in our probands. All patients had woolly hair since birth. At presentation, scalp hair density was reduced or normal. Sequencing of the LIPH gene revealed two homozygous mutations: a large recurrent 90-base pair duplication mutation in exon 2 in the Jewish and Arab families, and a novel deletion/insertion mutation in exon 4 in the Italian family. Only 3 families were studied. Mutations in LIPH result in variable degrees of HT. Woolly hair is an essential component of the clinical spectrum. A hot spot in the LIPH gene may be c.280_369dup in exon 2.