Advances in our knowledge about PWS and how to treat affected people to optimize their potential have largely resulted from research. Prior to 1981, when research first identified the genetic deletion on chromosome 15 as a cause of PWS, few scientists or physicians focused their efforts on PWS. In the subsequent 30 years, however, there has been an explosion of research efforts and resultant understanding about PWS. Through careful delineation of the clinical findings and establishment of clinical diagnostic criteria, geneticists have been able to determine that there are 3 major genetic causes of PWS (a small deletion on the paternally-contributed chromosome 15; maternal uniparental disomy 15—which is 2 maternally-contributed chromosome 15s and no paternal 15; and an abnormality in the process of controlling expression of the genes relevant to PWS on chromosome 15, called an imprinting defect). Improvements in our understanding about the cause of excessive eating in PWS have been identified as the general knowledge about hormonal substances and brain areas involved in appetite and satiety control have been elucidated. And much has been learned about the cognitive and behavioral difficulties that are characteristic of PWS. Perhaps most dramatically from a management perspective, researchers have determined that people with PWS have insufficient natural growth hormone, and found that treatment with growth hormone benefits affected children and adults in many ways, including not just height, but body composition, respiratory and sleep quality, physical appearance, energy and activity levels, and even cognitive ability. Despite all this progress, much remains to be learned.

Research is continuing on many aspects of PWS from all over the world and from multiple disciplines of medicine and science. Pharmaceutical companies have developed three new products to improve appetite control and/or weight loss, oxytocin, Modafinil (brand name Provigil) and Exenatide (marketed as Byetta); research into the effect of these substances on people with PWS is ongoing. New techniques for brain imaging are helping to uncover the brain processes that control appetite and satiety and interventions that can affect them in positive ways. Research geneticists are honing in on one gene that may be the major cause of many of the PWS manifestations, called SNORD116, a gene whose expression produces an RNA (not a protein) and whose targets are still being elucidated. Other genetic studies are seeking the cause of the variability in severity of the findings of PWS, and still others are seeking ways to influence PWS gene expression (a type of gene therapy) by inducing expression from suppressed genes in the PWS genetic region.

A large US collaborative project that involves several medical centers is working to extensively study a large group of individuals with PWS so that they will be prepared to conduct clinical trials of new treatments as soon as they are available. And support organizations for PWS both nationally and internationally are providing forums for communication among scientists, physicians, psychologists, and other researchers so that multidisciplinary efforts are facilitated.

The natural course of PWS has improved dramatically over the past 30 years largely because of research combined with educational efforts aimed at physicians (so diagnosis occurs early and accurately) and a wide range of other providers whose skills come to bear on people with PWS. It is anticipated that knowledge about PWS and its treatment will continue its exponential increase in the coming years through the efforts of researchers, physicians and other providers, organizations and families.

**Source: Dr. Suzanne Cassidy

NEW SONG written by Nancy Hellman Bechtle & Steve Earle
Mayim Bialik PhD, from the hit comedy series "The Big Bang Theory"