Maternal uniparental disomy for chromosome 15 leads to PWS because the genes on chromosome 15 that should have been inherited from the father are missing, and the genes on both the chromosome 15s inherited from the mother are imprinted.
This testing should also be offered to children and adults who display features commonly seen in PWS (developmental delays, uncontrollable appetite, small genitalia, etc.). There are several different genetic tests that can detect PWS.
With help, people with PWS can expect to accomplish many of the things their "normal" peers do: complete school, achieve in their outside areas of interest, be successfully employed, and even move away from their family home.
Although methylation testing can accurately diagnose PWS, it cannot determine if the PWS is caused by a deletion, maternal uniparental disomy, or a mutation that disrupts imprinting.
Individuals with PWS lack the ability to feel full or satiated because of a flaw in the hypothalamus part of their brain, which normally registers feelings of hunger and satiety.