Klinefelter syndrome

47,XXY; XXY syndrome; XXY trisomy

Klinefelter's syndrome is a condition caused by a chromosome nondisjunction in males; affected individuals have a pair of X sex chromosomes instead of just one, and is associated with additional risk for some medical conditions. It is named after Dr. Harry Klinefelter, a medical researcher at Massachusetts General Hospital, Boston, Massachusetts, who first described this condition in 1942.[1] Cause The XXY chromosome arrangement is one of the most common genetic variations from the XY k ...