The Genetics of Prader-Willi Syndrome

The Genetics of PWS: An Explaination for the Rest of Us

By Linda Keder, Editor, The Gathered View (Reproduced with permission from The Gathered View)
When the medical world first learned about Prader-Willi syndrome in 1956, doctors had no idea what caused people to have this collection of features and problems that we now know as PWS. It is only in the past 20 years that researchers have discovered the genetic changes on chromosome 15 that are responsible for the syndrome. In 1981, Dr. David Ledbetter and his colleagues reported a breakthrough discovery

The Three Genetic Forms of PWS

Although every case of Prader-Willi syndrome is due to the baby failing to receive active genes from a specific section of the father's chromosome 15, there are three different ways that this can happen

Genetic Tests Used to Diagnose PWS

Because the genetics of PWS is so complicated, it usually takes more than one test to be certain whether someone has PWS and what form of it they have. The major tests that are used in the diagnosis of PWS are shown in the table. Which genetic tests are used, and in what order, will depend on a number of considerations