First-trimester diagnosis of Smith-Lemli-Opitz syndrome.
We report here the prenatal diagnosis of Smith-Lemli-Opitz (SLO) syndrome in the first trimester by direct measurement of 7-dehydrocholesterol (7-DHC) in a chorionic villus (CV) biopsy. The proband was diagnosed clinically at birth and the diagnosis was confirmed biochemically by demonstrating elevated 7-DHC in plasma. The family pursued prenatal diagnosis in their fourth, fifth, and sixth pregnancies. The fourth pregnancy spontaneously miscarried at 9 weeks' gestation. Analysis in both direct and cultured curetting tissue (identified as similar to CV tissue) showed an abnormal tissue neutral sterol pattern with an elevated 7-DHC concentration. The fifth pregnancy also miscarried spontaneously at 9 weeks but no tissue of unequivocal fetal origin could be identified to allow biochemical investigation. In the sixth pregnancy, ultrasound examination at the time of CV sampling showed a thickened nuchal fold. Direct analysis of the CV sample revealed elevated levels of 7-DHC consistent with the diagnosis of SLO. The pregnancy was terminated and both fetal tissue and cultured fetal cells showed marked increases in 7-DHC, confirming the prenatal diagnosis.
Sharp
P
P
Department of Chemical Pathology, Women's and Children's Hospital, North Adelaide, Australia.
Haan
E
E
Fletcher
J M
JM
Khong
T Y
TY
Carey
W F
WF
D002478:Cells, Cultured; D002824:Chorionic Villi / Q000737:chemistry; D003684:Dehydrocholesterols / Q000032:analysis; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis; D019082:Smith-Lemli-Opitz Syndrome / Q000175:diagnosis*
D003684:Dehydrocholesterols; C016705:7-dehydrocholesterol