Novel DHCR7 mutation in a case of Smith–Lemli–Opitz syndrome showing 46,XY disorder of sex development

Smith–Lemli–Opitz syndrome is an autosomal recessive disease caused by mutations in 7-dehydrocholesterol reductase ( DHCR7 ), which is rarely observed in Japan. We report a Japanese case with 46,XY disorder of sex development and Y-shaped 2–3 toe syndactyly. DHCR7 gene analysis revealed compound heterozygous mutations including the novel mutation H442R. Early diagnosis led to starting cholesterol treatment at an early age.