Angelman syndrome is a neurogenetic disorder caused by a chromosome disorder that causes severe learning disabilities. It is thought that angelman syndrome occurs in about 1 in 10,000 births. Angelman syndrome is characterised by intellectual and developmental delay. Two of the most prominent behavioural characteristics are inappropriate laughter and speech deficits. Communication can be difficult at first, but as a child with Angelman syndrome develops, there is a definite character and an ability to make themselves understood. It is widely recognised that receptive communication skills tend to exceed expressive communication skills. In addition, the following behavioural characteristics have been observed to varying degrees: sleep disturbance, seizures, jerky movements (especially hand-flapping), frequent laughter or smiling, and usually a happy demeanor. People with angelman syndrome exhibit a profound desire for personal interaction with others.