Angelman's Syndrome is a genetic disorder caused by the lack of chromosome 15, one of the 23 paired chromosomes, from the mother. It gets its name from the pediatrician who first noted the symptoms, Dr. Angelman. That, along with the characteristic happiness that goes with the condition earns patients the name "angels." This happiness shows up in the form of laughter, clapping and excitability. Other characteristics are slowed development with little or no speech, lack of physical coordination, seizures, and sleep disturbances.