Molecular Genetic Findings in Prader-Willi Syndrome

Abstract

Prader-Willi syndrome (PWS), the most common genetic cause of marked obesity in humans, is due to loss of expression of paternal genes from the 15q11–q13 region under the control of an imprinting center. PWS and Angelman syndrome, an entirely different clinical condition due to lack of maternally expressed genes, were the fi rst examples in humans of genomic imprinting. There are three recognized genetic subtypes in PWS, including paternally derived interstitial deletions of the 15q11–q13 region, maternal uniparental disomy 15 (both 15 s from the mother), and imprinting defects.