Phenotype-karyotype-genotype correlations in Prader-Willi and Angelman syndromes: preliminary results.

Abstract

Prader-Willi Syndrome (PWS) and Angelman Syndrome (AS) are well established as models of Genomic Imprinting in humans, since completely different phenotypes are generated by the absence of paternal (PWS) or maternal (AS) contribution to the q11-13 region of chromosome 15 as a result of deletion or uniparental disomy. We report a preliminary study based on our experience of more than 20 years of research into the genetics of PWS and AS syndromes.Thirty nine subjects, referred from a number of Centers and Medical Doctors have been examined to either confirm or rule out a diagnosis of PWS or AS.Patients were evaluated through the Clinical Genetics and Dysmorphology Program at the Human Genetics Center, Dept. of Paediatrics, University of Florence.Clinical evaluation showed that 10 of these patients fulfilled diagnostic criteria for PWS and 8 for AS.All patients were isolated cases and the 18 nuclear families were unrelated.We adopted the staged diagnostic approach for all our families diagnosed PWS or AS families, moleucular using cytogenetic, genetic and molecular cytogenetic techniques.