A.S occurs when there is an abnormality in chromosome fifteen (Angelman Syndrome begins at birth.) Most likely, one of these genes controls the brain development, especially the parts that deal with language, movement, and pigmentation. It also seems that some of these genes influence the transmission of messages inside the brain. The gene that carries Angelman syndrome can only be found on the maternal chromosome. The first seven genes are deleted from this portion causing Prader-Willi syndrome, which is only found on the paternal chromosome. Therefore, it is possible for the father with A.S to pass this disease on to his daughter, who has Prader-Willi syndrome. This is known to be the first known instance of imprinting. Imprinting is the silencing of certain genes and chromosomes.

This genetic disorder includes a great amount of features. Seventy-five percent of the population with A.S has feeding problems...