Prader-Willi Syndrome


 * About 2/3 of cases are induced by the loss of paternal chromosome 15 segment (The Prader-Willi/Angelman Critical Region- PWACR; 15q11-13). Physiologically, just genes in the paternal region are functional (the maternal copies are imprinted, i.e. epigenetically silenced) - opposite to Angelman syndrome.
 * Typical symptoms: hypotonia, obesity, poor growth, delayed development and higher appetite (hyperphagia - leads to overeating).
 * Children have also problems with their learning abilities and behavior. We can also find typical physical features - smaller feet and hands, fair skin, underdeveloped genitals (hypogonadism). Some of the affected patients are infertile.
 * Incidence of Prader-Willi syndrome is 1 in 10 000 - 30 000 people worldwide.

Related articles

 * Genomic Imprinting
 * Angelman syndrome
 * Gene
 * Allele
 * Chromosome