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Name: Karin Chuoke
Status: Other
Grade:  Other
Location: VA
Country: United States
Date: December 2005

If a male is born with XX sex chromosome (XX Male syndrome), What characteristics can be expected from these individuals?

Occasionally an individual receives the incorrect number of chromosomes. Most of these combinations are lethal, and the mother may not even know that she is pregnant before the very young embryo is passed in what appears to be a normal menstrual flow. In a few cases, the unusual combination is viable. Down's syndrome, for example, results when an individual has three copies of chromosome 21, instead of the usual two. Another example is when individuals receive the incorrect number of copies of the sex chromosomes, X and Y.

A variety of combinations have been observed: XXY, XXX, XYY, etc. In the case of XXY individuals, the person has what is called Klinefelter Syndrome. Many of these individuals are capable of sexual intercourse, but they are often sterile, due to underdeveloped testes. A lower than normal amount of testosterone is produced, leading to lowered amounts of muscle mass and lowered energy levels compared to XY males. The body may show some feminine traits, e.g., partial development of breast tissue, lack of facial hair, etc. The brain structure is altered somewhat, and learning disabilities may be observed. These days, XXY males can be given testosterone shots during puberty, to counteract the low levels of testosterone produced.

The presence of abnormal numbers of sex chromosomes is not related to homosexual tendencies. In other words, homosexual individuals do not have abnormal chromosome numbers, and Klinefelter individuals are not necessarily homosexual.

Paul Mahoney, PhD

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