Novel 7‐DHCR mutation in a child with Smith‐Lemli‐Opitz syndrome

Smith‐Lemli‐Opitz syndrome (SLOS) is an autosomal recessive disorder characterized by minor facial anomalies, mental retardation, and multiple congenital abnormalities. Biochemically, the disorder is caused by deficient activity of 7‐dehydrocholesterol reductase, which catalyzes the reduction of the Δ7 double bond of 7‐dehydrocholesterol to produce cholesterol. Recently, mutations in the gene encoding 7‐dehydrocholesterol reductase (7DHCR) were found to cause SLOS. We report the first molecular characterization of an Italian SLOS patient. Interestingly, his paternal 7DHCR allele, of Arab origin, harbored a novel P329L mutation which in combination with a maternal splice‐site (IVS8‐1 G>C) mutation resulted in a relatively milder phenotype. Am. J. Med. Genet. 91:138–140, 2000. © 2000 Wiley‐Liss, Inc.