Angel syndrome is a genetic defect caused by the disease, the patient’s face is often smiling, lack of language skills, hyperactivity, mental retardation, patients often waved his hands up, poor balance, this disease will not spread. The cause of angel syndrome is caused by genetic defects, is the loss of chromosome 15 q11-q13 caused. This disease is caused by a single gene genetic defects. Due to a partial defect in the 15q region of the 15th chromosome imprinting gene from the mother, or both chromosome 15 with this defect from the father. On the contrary, if the genetic defect from the father, or have two from the mother of genetic defects.