Definition of XYY syndrome
XYY syndrome: A chromosomal disorder that affects males only, caused by the presence of an extra Y chromosome. Symptoms may include increased height, speech delays, learning disabilities, mild to moderate mental retardation, and behavioral disturbance. Also known as polysomy Y syndrome.
Last Editorial Review: 8/28/2013
Back to MedTerms online medical dictionary A-Z List
Need help identifying pills and medications?