Fetal Smith-Lemli-Opitz syndrome can be detected accurately and reliably by measuring amniotic fluid dehydrocholesterols

✍ Scribed by G. S. Tint; Dianne Abuelo; Marianne Till; M. P. Cordier; Ashok K. Batta; Sarah Shefer; Akira Honda; Megumi Honda; Guorong Xu; Mira Irons; Ellen R. Elias; Gerald Salen

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 226 KB
• Volume: 18
• Category: Article
• ISSN: 0197-3851
• DOI: 10.1002/(sici)1097-0223(199807)18:7<651::aid-pd316>3.0.co;2-v

✦ Synopsis

The Smith-Lemli-Opitz syndrome, characterized by limb, face and organ abnormalities, and mental retardation, is caused by an inherited block in the step of cholesterol biosynthesis in which the 7 double bond of 7-dehydrocholesterol is reduced. It is diagnosed by the presence of markedly elevated levels of 7-dehydrocholesterol and 8-dehydrocholesterol in plasma and tissue. We measured amniotic fluid sterols in 15 pregnancies in 13 women who had previously carried an affected fetus. Cholesterol, 7-dehydrocholesterol and 8-dehydrocholesterol concentrations averaged 18 3, 9•8 2•9 and 5•0 1•7 g/ml, respectively, in seven pregnancies with an affected fetus or child. In contrast, these levels were 19 3, 0•05 0•01 and <0•005 g/ml, respectively, in eight increasedrisk pregnancies with normal outcomes and 16 2, 0•07 0•01 and <0•005 g/ml in normal controls. 7-dehydrocholesterol concentrations, 2•2-26 and 0•05-0•10 g/ml in pregnancies with an affected and unaffected fetus, respectively, did not overlap. Thus, abnormally elevated amniotic fluid dehydrocholesterol concentrations are an accurate predictor of fetal Smith-Lemli-Opitz syndrome. A false-positive or a false-negative result is highly unlikely. 1998 John Wiley & Sons, Ltd.