Incidence of Smith-Lemli-Opitz syndrome in Canada: results of three-year population surveillance

J Pediatr. 2004 Oct;145(4):530-5. doi: 10.1016/j.jpeds.2004.06.045.

Abstract

Objectives: To determine the incidence and point prevalence of Smith-Lemli-Opitz syndrome (SLOS) in Canada; to determine the percentage of mild cases of SLOS; and to determine the age of diagnosis of mildly affected patients. SLOS is a treatable genetic condition that may be difficult to diagnose in its mildest form because of nonspecific clinical markers (two- to three-toe webbing, short upturned nose, and micrognathia).

Study design: More than 2000 Canadian pediatricians and pediatric specialists were surveyed monthly for 36 months through a standing national surveillance program. A clinical identification form was designed to identify patients with SLOS or its phenocopies. Clinical information was obtained on all reported cases; suggested cases were investigated by biochemical or molecular analysis.

Results: Thirty-five of 86 reports of suggested SLOS were confirmed SLOS. Twelve infants with SLOS were born during the surveillance period, and two additional infants with SLOS were diagnosed prenatally. Twenty-one infants with SLOS were born before the onset of surveillance.

Conclusions: The minimum incidence of SLOS in Canada is 1 in 70,358 live births. The minimum prevalence of SLOS is approximately 1 in 950,000. Eighteen percent of patients were mildly affected; the mean age of diagnosis of mildly affected patients was 5.3 years.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Canada / epidemiology
  • Child
  • Child, Preschool
  • Humans
  • Incidence
  • Infant
  • Infant, Newborn
  • Population Surveillance*
  • Prevalence
  • Prospective Studies
  • Smith-Lemli-Opitz Syndrome / epidemiology*
  • White People / statistics & numerical data