All issues > Volume 51(11); 2008

Case Report

Korean J Pediatr. 2008;51(11):1236-1240. Published online November 15, 2008.

A case of Smith-Lemli-Opitz syndrome diagnosed by identification of mutations in the 7-dehydrocholesterol reductase (DHCR7) gene

Mee Rim MR Park¹, Jung Min JM Ko¹, Chong-Keun CK Cheon¹, Gu-Hwan GH Kim², Han-Wook HW Yoo¹

¹Department of Pediatrics, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Korea
²Medical Genetics Clinic and Laboratory, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Korea

Correspondence Han-Wook HW Yoo ,Email: hwyoo@amc.seoul.kr

Abstract

Smith-Lemli-Opitz syndrome (SLOS) is a rare, autosomal recessive disease caused by an inborn error in cholesterol synthesis. Patients with this disease suffer from multiple malformations due to reduced activity of 7-dehydrocholesterol reductase (DHCR7), which increases 7-dehydrocholesterol (7DHC) and 8-dehydrocholesterol (8DHC) concentrations and decreases cholesterol concentration in body fluids and tissue. The SLOS phenotypic spectrum ranges from a mild disorder with behavioral and learning problems to a lethal disease characterized by multiple malformations. Here, we describe a newborn male with ambiguous genitalia who was diagnosed to have type II SLOS during the neonatal period. A clinical examination revealed low levels of unconjugated estriol in the maternal serum, and a variety of fetal ultrasound anomalies, including prenatal growth retardation. After birth, the infant was diagnosed to have congenital heart disease (Tetralogy of Fallot with severe pulmonary artery stenosis), cleft lip and palate, micrognathia, postaxial polydactyly, ambiguous genitalia, and cataracts. Clinical investigation revealed extremely low plasma cholesterol levels and the presence of mutation (homozygote of p.Arg352Gln) in the DHCR7 gene. The patient underwent palliative heart surgery (to widen the pulmonary artery) and received intravenous lipid supplementation. Cholesterol levels increased slightly, but not to normal values. The patient died from cardiopulmonary failure and sepsis 72 days after birth. This report provides the first description of a Korean patient with SLOS confirmed by verification of DHCR7 gene mutation and illustrates the need for early recognition and appropriate diagnosis of this disease.

Keywords :Smith-Lemli-Opitz syndrome, Multiple malformations, 7-dehydrocholesterol reductase, Cholesterol