Disorders of cholesterol biosynthesis have clinical manifestations involving skeleton, eyes, neurologic development, and skin. We describe a patient with congenital cataracts, developmental delay, microcephaly, and low serum cholesterol who developed severe psoriasiform dermatitis and arthralgias beginning at age 3. Her brain MRI indicatedminor gliosis. Quantitative sterol analysis of patient plasma and skin showed marked elevation of 4alpha-methyl- and 4, 4'-dimethylsterols, indicating a deficiency in the first step of sterol C4 demethylation in cholesterol biosynthesis. Molecular studies showed mutations in _SC4MOL_, a gene predicted to encode a sterol C4 methyl oxidase. Thus, our patient has a previously undescribed inborn error of cholesterol... |