Klinefelter's Syndrome is the most frequent sex chromosomal genetic disorder and is caused by the presence of an extra X chromosome
Klinefelter Syndrome (KS), like Turner's Syndrome, is a sex chromosomal disorder and was described and named after the physician who described it. While KS individuals have an extra X- chromosomes or 47 chromosomes, a person with Turner's lack a X chromosome and has a total of 45 chromosomes.
Klinefelter Syndrome (KS), was first described by Dr. Harry Klinefelter and his colleagues in 1942, while studying nine men with fertility problems and enlarged breasts. They found that the condition occurred only in males and was usually not identified until after puberty. It took another ten long years for Patricia Jacobs and J.A. Strong to demonstrate that the majority of males with KS have 47 chromosomes.
Klinefelter's Syndrome, which affects 1 in 500 to 1 in 1000 live births, is a sex chromosomal genetic disorder where the affected males have an extra X chromosome. These individuals are also referred to as 'males with XXY syndrome'
, or as 'XXY males'
.This is not an inherited disorder.
Normal sexual development is seen in infancy and childhood. Although the onset of puberty is not delayed, the post-pubertal developments are inadequate in comparison to normal males. KS adolescents have low levels of confidence compared to other boys of the same age.
Although their educational achievements tend to be poor compared to their contemporaries, many KS patients show normal intelligence and function well in society. Most of them complete college and reach high positions professionally. These individuals may live their entire lives without the slightest doubt that they are in any way unusual.
Nine cases are presented of a syndrome characterized by gynecomastia, and small testes with aspermatogenesis but without a-leydigism. The follicle-stimulating hormone (FSH) excretion in the urine is increased to a degree comparable to that found in castrates…. These studies support the point of view that the testis produces two hormones;
a) androgen from the Leydig cells,
b) X-hormone (inhibin) from the tubules. Inhibin is analogous and probably very similar to estrin.
Harry Fitch Klinefelter, Edward C. Reifenstein Jr., Fuller Albright, 1942