User:Mr. Ibrahem/XYY syndrome

XYY syndrome is a genetic condition in which a male has an extra Y chromosome. There are usually few symptoms. These may include being taller than average, acne, and an increased risk of learning problems. The person is generally otherwise normal, including normal fertility.

The condition is generally not inherited from a person's parents but rather occurs as a result of a random event during sperm development. Diagnosis is by a chromosomal analysis, but most of those affected are not diagnosed within their lifetime. There are 47 chromosomes, instead of the usual 46, giving a 47,XYY karyotype.

Treatment may include speech therapy or extra help with schoolwork, but outcomes are generally good. The condition occurs in about 1 in 1,000 male births. Many people with the condition are unaware that they have it. The condition was first described in 1961.