P601: Clinical Utility of MS-MLPA for the Diagnosis of Prader-Willi/Angelman Syndrome: the GGC Experience

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are genomic imprinting disorders, mapped to chromosome 15q11.2-q13, which are caused by copy number changes, uniparental disomy of chromosome 15 (UPD15), imprinting center (IC) defects in the critical region, and single nucleotide variants. Therefore, establishing or ruling out a molecular diagnosis of PWS/AS presents unique challenges due to various genetic etiologies. The Methylation-Specific Multiplex Ligation-Dependent Probe Amplification (MS-MLPA) kit (MRC Holland) is clinically validated by our laboratory, and the findings and experience after diagnostic testing of 86 clinical cases are presented here.