Incidence of Smith-Lemli-Opitz syndrome in Ontario, Canada

Citation
Mjm. Nowaczyk et al., Incidence of Smith-Lemli-Opitz syndrome in Ontario, Canada, AM J MED G, 102(1), 2001, pp. 18-20
Citations number
22
Categorie Soggetti
Molecular Biology & Genetics
Journal title
AMERICAN JOURNAL OF MEDICAL GENETICS
ISSN journal
01487299 → ACNP
Volume
102
Issue
1
Year of publication
2001
Pages
18 - 20
Database
ISI
SICI code
0148-7299(20010722)102:1<18:IOSSIO>2.0.ZU;2-T
Abstract
Smith-Lemli-Opitz syndrome (OMIM 270400) (SLOS) is caused by inherited enzy matic deficiency of 3 beta -hydroxysterol-Delta (7)-reductase (7-dehydrocho lesterol-Delta (7)-reductase, DHCR7). SLOS is diagnosed clinically by the d emonstration of elevated levels of 7-dehydrocholesterol (7DHC) in body flui ds or tissues. SLOS is associated with mental retardation of variable degre e and severe behavior abnormalities. The physical abnormalities range from minor facial anomalies to lethal malformations of the central nervous syste m, heart, kidneys, and other organs. The exact incidence of SLOS is not kno wn. Although there exist estimates of the incidence of SLOS ranging from 1 in 20,000 to 1 in 60,000, no prospective studies of the incidence of SLOS, based on the clinical data and biochemical diagnosis of SLOS, have been per formed. Five unrelated cases of SLOS were diagnosed in Ontario during a 12- month period. The diagnoses were made based on the demonstration of elevate d 7DHC in plasma or amniotic fluid. The birth rate for Ontario for that per iod was 132,000 births, The incidence of SLOS in Ontario was at least 1 in 26,500 pregnancies in 1999-2000. Given that 86% of the population of Ontari o is of European origin, the incidence of SLOS in the Ontario population of European origin was at least 1 in 22,700. As infants with mild forms of SL OS born during this period may remain undiagnosed, these numbers likely are underestimates. This observation has implications for prenatal and newborn screening for this potentially treatable inherited disorder. (C) 2001 Wile y-Liss, Inc.