Angelman syndrome facts*

*Angelman syndrome facts Medically Edited by: Melissa Conrad Stöppler

• Angelman syndrome is a genetic disorder with characteristic features that include severe speech impairment, developmental delay, intellectual disability, and ataxia (problems with movement and balance).
• Angelman syndrome is named after the physician Harry Angelman who first delineated the syndrome in 1965.
• Angelman syndrome affects an estimated 1 in 12,000 to 20,000 people.
• Most children with Angelman syndrome have microcephaly (small head size) and epilepsy (recurrent seizures).
• The developmental delay of Angelman syndrome generally becomes noticeable by the age of 6 to 12 months.
• Adults with Angelman syndrome have facial features that are distinct and are often described as "coarse."
• Some of the characteristic features of Angelman syndrome are a result from the loss of function of a gene called UBE3A.
• The life expectancy for individuals with Angelman syndrome appears to be nearly normal.

What is Angelman Syndrome?

Angelman syndrome is a genetic disorder that causes developmental delay and neurological problems. The physician Harry Angelman first delineated the syndrome in 1965, when he described several children in his practice as having "flat heads, jerky movements, protruding tongues, and bouts of laughter."