Abstract for presentation at 11th International Congress of Human Genetics

Incidence of Smith-Lemli-Opitz syndrome in Poland: preliminary results

  • MD, PhD Malgorzata Krajewska-Walasek, Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
  • Dr Elzbieta Ciara, Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
  • Dr Ewa Malunowicz, Department of Laboratory Diagnostics, The Children's Memorial Health Institute, Warsaw, Poland
  • Dr Dorota Piekutowska-Abramczuk, Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
  • Dr Anna Materna-Kiryluk, Department of Medical Genetics, University of Medical Sciences, Poznan, Poland
  • Krystyna Chrzanowska, Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
  • Dr Ewa Popowska, Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
  • MD, PhD Anna Latos-Bielenska, Department of Medical Genetics, University of Medical Sciences, Poznan, Poland

    • Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder of cholesterol biosynthesis caused by mutations in the DHCR7 gene. The incidence of SLOS may be as high as 1 in 15,000 to 1 in 60,000. The last studies indicate that the disease carrier rate is approximately 1 in 100 (1%) to 1 in 50-30 (2 -3,3%) in some populations. In sixty three Polish patients with SLOS we identified 15 DHCR7 mutations. Two mutations, p.Trp151X and p.Val326Leu, account for 65.2% of all observed DHCR7 changes. The both mutations were used as markers of the disease to determine the carrier frequency of SLOS in Poland. Our population screening in 4256 anonymous neonates indicated the carrier frequency of these two mutations as 2.40±0.32%. Estimated SLOS incidence in Poland, calculated according to Hardy-Weinberg’s law, is 1 in 3,937 to 1 in 2,300. The expected disease incidence would place SLOS among the most common recessive genetic disorders in Poland.
    The discrepancy between estimated and observed incidence of SLOS may be explained by the identification mainly the patients with severe SLOS, prenatal/neonatal mortality of the most severely affected fetuses/ undiagnosed newborn infants.
    From the beginning of this year the actual incidence of SLOS in Poland is investigated by Polish Register of Birth Defects using a 3-year prospective study identifying all new cases of SLOS. More than 2000 Polish pediatricians, clinical geneticists, and obstetricians have begun to identify and report cases of SLOS. The organization of a national surveillance program and the preliminary results will be presented.
    The study was supported in part by Projects No. 1/PBZ/02 and PBZ-KBN-122/P05/01-10.

    Conference Organiser - ICMS Pty Ltd