Klinefelter's syndrome


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Related to Klinefelter's syndrome: Androgen insensitivity syndrome, XYY syndrome

Klinefelter's syndrome

 [klīn´fel-terz]
a condition in males characterized by small testes, with fibrosis and hyalinization of seminiferous tubules, impairment of function and clumping of Leydig cells, and an increase in urinary gonadotropins, associated with an abnormality of the sex chromosomes. It is associated typically with an XXY chromosome complement.
Klinefelter's syndrome. Redrawn from Damjanov, 2000.

Klinefelter's syndrome

[klīn′feltərz]
Etymology: Harry F. Klinefelter, American physician, 1912-1990
a condition of gonadal defects appearing in males after puberty, caused by an extra X chromosome in at least one cell line. Characteristics are small firm testes, long legs, gynecomastia, poor social adaptation, subnormal intelligence, chronic pulmonary disease, and varicose veins. The severity of the abnormalities increases with greater numbers of X chromosomes. The most common abnormality is a 47 XXY karyotype. Men with the karyotype XXXXY have marked congenital malformations and mental retardation.
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Klinefelter's syndrome

Klinefelter syndrome

A syndrome with a 47, XXY chromosome complement, in which the subjects are phenotypically male but have seminiferous tubule dysgenesis, elevated plasma and urinary gonadotropins, variable gynecomastia, eunuchoid habitus and possibly female secondary sex characteristics. Some patients are chromosomal mosaics, with two or more cell lines of different chromosome constitution.

Klinefelter's syndrome

A male bodily disorder caused by one or more additional X (sex) chromosomes. Instead of the normal X and Y sex chromosomes, men with Klinefelter's syndrome have an XXY configuration. This has a feminizing effect. The penis and testicles are small and there may be female breast development and diminished sexual interest (libido). Homosexuality and transvestism are common. The diagnosis can easily be confirmed by chromosomal analysis. Hormonal and plastic surgical treatment can help. (Harry Fitch Kleinfelter, American physician, b. 1912)

Klinefelter's syndrome

a human chromosomal abnormality in which there is an extra X-chromosome making a complement of 44 autosomes plus XXY (47 in all). The affected individuals are male (showing the SEX DETERMINATION role of the Y-chromosomes) but with much reduced fertility, and a number of female secondary sexual characteristics, such as breasts, often occur. About 1 in 1000 liveborn males are affected by this condition, which arises from NONDISJUNCTION in one or other parent, more probably the female where there is a distinct positive age effect (as in DOWN'S SYNDROME).

Klinefelter's syndrome

Chromosomal abnormality characterized by small testes and male infertility.

Klinefelter's syndrome

a condition in humans characterized by the presence of small testes, with fibrosis and hyalinization of the seminiferous tubules, impairment of function and clumping of Leydig cells, and an increase in urinary gonadotropins, associated with an abnormality of the sex chromosomes. It is associated typically with an XXY chromosome complement. A similar condition is seen in male tortoiseshell and white cats, and has been recorded rarely in stallions, bulls, rams and dogs.

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References in periodicals archive ?
The effects of testosterone treatment in Klinefelter's syndrome.
Thus, there is an option for cryopreservation of sperm in adolescents with Klinefelter's syndrome (De Sanctis & Ciccone, 2010).
For example, in a cytogenetic study on a large Dutch infertile population (1792 infertile men) as low as 72 cases (4%) with chromosomal abnormalities were reported and Klinefelter's syndrome (either pure or mosaic form) was found in just 12 patients (0.
CHICAGO -- The majority of young patients with Turner's syndrome and Klinefelter's syndrome fall through the cracks in the health care system as they make the transition into adulthood.
Jackson has Klinefelter's Syndrome which is caused by having an extra sex chromosome.
Among the 155 couples with unconsummated marriages, physical findings among the men included five previously undiagnosed primary adenomas and an equal number of previously undiagnosed cases of phimosis, along with one case of Klinefelter's syndrome and one case of hypogonadism.
The addition of an extra X chromosome to a normal male chromosomal makeup results in a condition termed Klinefelter's syndrome (XXY).
We present the case of a man with recurrent leg ulcers who was recognized as hypogonadal and was ultimately given the diagnosis of Klinefelter's syndrome (XXY) at age 47.
Gynecomastia also may occur in conjunction with cancer of the testes or adrenal glands, cirrhosis of the liver, chronic renal dialysis or a chromosomal disorder known as Klinefelter's syndrome.
Chromosomal problems such as Down's syndrome, Turner's syndrome, or Klinefelter's syndrome are not inherited in the sense that a parent must either have the condition or be a carrier of the corresponding genes; rather, such conditions result from errors in the transmission of genetic material.
While researchers debate the causes, the American Cancer Society says doctors agree that male breast cancer is attributable to certain risk factors, such as abnormal levels of estrogen; Klinefelter's syndrome, a male genetic disorder; gynecomastia, enlargement of male breast tissue; obesity; radiation exposure; and age (the average victim is 64).