Prader-Willi and angelman syndromes

Abstract

Since the first report of nine similarly affected individuals by Prader and colleagues in 1956, a wealth of information has accumulated regarding the medical pathophysiology, genetic, and natural history of this disorder which carries the name of two of the clinicians first reporting this disorder, i.e., Prader-Willi syndrome (PWS). Clinical criteria and chromosome studies were used for diagnosis until more accurate molecular genetic testing became available in the mid- to late 1990s. In 2000, the identification of growth hormone deficiency was recognized, and approval was made for growth hormone use in this rare disorder. Advances made during the past decade have led to a new level of recognition, intervention, and description of PWS useful for identification and characterization of the genetics and medical aspects at all ages from infancy to adulthood. This review is dedicated to exploring the current understanding and cause of Prader-Will syndrome and comparison with its sister syndrome, Angelman syndrome (AS). PWS and AS were the first examples in humans of genomic imprinting whereby the differential expression of genetic information depends on the parent of origin. They both occur in about one in 10,000-30,000 individuals with PWS estimated to affect approximately 400,000 people worldwide but disproportionately more in Caucasians.