LSS and cataract: For example, approximately 20% of patients with Smith Lemli Opitz syndrome who are deficient in DHCR7 have cataract227; the missense mutation of lanosterol synthase (LSS, cyclinase in cholesterol biosynthesis) causes cataract in pedigree analysis of close relatives of Caucasian descent; cataracts occur in approximately 30% of patients with mevalonate aciduria caused by mevalonate kinase deficiency.228