Navigation Links
Klinefelter's syndrome

Klinefelter's syndrome is a condition caused by a chromosome abnormality in males (specifically, a nondisjunction); sufferers have a pair of X sex chromosomes instead of just one. It is named after Harry Klinefelter , the medical researcher who first described this syndrome in 1942.

Human males usually have an XY karyotype. The XXY chromosome arrangement is one of the most common genetic abnormalities, occurring in about 1 in 1,000 male births, but the symptoms that may result from having the extra chromosome are less common. Because of this extra chromosome, individuals with the abnormality are usually referred to as "XXY Males" rather than as "suffering from Klinefelter's syndrome."

In mammals with more than one X chromosome, the genes on all but one X chromosome are barred from being expressed. This happens in XXY males as well as XX females. A few genes, however, have corresponding genes on the Y chromosome and are not barred. These triploid genes in XXY males may be responsible for the symptoms of Klinefelter's syndrome.

In adults, the syndrome is characterised by gynecomastia (enlarged breasts), a rounded body type with abnormal body proportions, sparse facial and body hair, small testes, and an inability to produce sperm. Most XXY males have some degree of language impairment as well. The syndrome is associated with an increased risk of breast cancer, pulmonary disease , varicose veins, and osteoporosis.

The condition was identified in 1942 by Dr. Harry Klinefelter in Boston. The cause was not found until the 1950s. The condition is incurable, but its symptoms can be treated in a number of ways, including testosterone treatment and other therapies.

While the gender identity of people with XXY karyotype is usually male, the number of people with a female gender identity among them seems to be higher than could statistically be expected if those cases were indeed, as the current medical opinion assesses, mere coincidences of people having both gender identity disorder and Klinefelter's independently from each other. This observation however is based on the reports of support groups for transgender and transsexual people, no scientific study on this subject has been done. The fact that a person undergoing treatment for gender identity disorder has Klinefelter's syndrome is often missed or the patient is not told, although in many jurisdictions this additional diagnosis can have legal consequences, for example regarding name change. Also, the medical treatment may have to be adapted.

External links

See also


(Date:8/22/2014)... French . NAIROBI (22 ... soils looming as a major threat to food security across ... the last five years, 1.7 million African farmers in 13 ... hectares and helped them double or even triple crop yields. ... in Africa (AGRA) focuses on intensive efforts initiated five years ...
(Date:8/22/2014)... 2014 Diabetes affects nearly 10 percent of ... diabetics: constant finger pricking to test blood glucose ... reports the development of a protein that could ... for diabetes patients. In the American Chemical Society,s ... shows off her "designer protein" that could eventually ...
(Date:8/22/2014)... MD FASEB MARC (Maximizing Access to Research Careers) ... FASEB Grant Writing Seminar & Practical Exercises Workshop which ... Bethesda, Maryland from August 25-26, 2014. These awards ... and research scientists from underrepresented groups in the the ... This year MARC conferred 11 awards totaling $20,350. , ...
Breaking Biology News(10 mins):Effort to confront Africa's soil health crisis helps millions of farmers triple yields 2Effort to confront Africa's soil health crisis helps millions of farmers triple yields 3Effort to confront Africa's soil health crisis helps millions of farmers triple yields 4
... light on the causes of Parkinson,s disease, researchers report that ... mitochondria. A shutdown in fuel can have devastating effects on ... energy despite making up only 2 percent of body weight. ... FDA approved drugs early on may prevent or delay the ...
... CAMBRIDGE, Mass. -- By creating a better way to ... with MIT,s Picower Institute for Learning and Memory and the ... synapse formation. These studies could also help further understanding of ... and Fragile X syndrome. The study will appear in the ...
... their dosages may be standardized, but not every patient ... personal genetic characteristics of individuals and populations can explain ... not another, so medical researchers are adopting the new ... lab is leading the way. Dr. Noam ...
Cached Biology News:In Parkinson's disease, brain cells abandon mitochondria, researchers report 2In Parkinson's disease, brain cells abandon mitochondria, researchers report 3MIT researchers develop a better way to see molecules at work in living brain cells 2An X-ray for your genes 2
Other biology definitionOther Tags