A rare chromosomal genetic syndrome where the male person has an extra Y male chromosome, becoming XYY instead of normal XY (male) or XX (female). The person is male and may be mostly normal, or may suffer from minor features from excess male hormones, such as excess acne being very tall, and in some cases behavioral complaints such as aggression.
47,XYY is not inherited, but usually occurs as a random event during the formation of sperm cells. An error in chromosome separation during metaphase II (of meiosis II) called nondisjunction can result in sperm cells with an extra copy of the Y chromosome. If one of these atypical sperm cells contributes to the genetic makeup of a child, the child will have an extra Y chromosome in each of the body\'s cells.
In some cases, the addition of an extra Y chromosome results from nondisjunction during cell division during a post-zygotic mitosis in early embryonic development. This can produce 46,XY/47,XYY mosaics
Effective management relieves pain with analgesics and immobilization using crutches, splints, braces, and restriction of weight bearing to the affected joint.
In severe disease, surgery may include arthrodesis or, in severe diabetic neuropathy, amputation. However, surgery risks further damage through nonunion and infection.