Disorder in Sterol Metabolism

A New Disorder in Sterol Metabolism

Defects in cholesterol synthesis result in a wide variety of symptoms from neonatal lethality to the relatively mild dysmorphic features and developmental delay found in Smith-Lemli-Opitz syndrome (SLOS). Our investigation identified mutations in SC4MOL as the cause of a newly recognized autosomal recessive syndrome that includes psoriasiform dermatitis, arthralgias, congenital cataracts, microcephaly, and developmental delay. This gene encodes a sterol-C4-methyl-oxidase, catalyzing demethylation of C4-methylsterols in the cholesterol synthesis pathway. C4-methylsterols are members of meiosis-activating sterols (MAS). They are first found in high concentration in testis and ovary and play roles in meiosis activation.

In this study, our team found that MAS affect the cell proliferation in both skin and blood. We also found that inhibition of sterol-C4-methyl-oxidase significantly altered the immune regulation in immunocytes. MAS are ligands of the liver X receptors α and β, which are important in regulating not only lipid transport in epidermis, but also the innate and adaptive immunity. Deficiency of SC4MOL represents a new biochemical defect in the cholesterol synthesis pathway, the clinical spectrum of which remains to be defined.

Principal Investigator

Gerard Vockley, MD, PhD