These include personality changes, depression, and psychosis. Klinefelter's syndrome is the most common genetic cause of human male infertility, but many cases remain undiagnosed because of substantial variation in clinical presentation and insufficient professional awareness of the syndrome itself. Signs and symptoms vary greatly. Article Translations: What Is Klinefelter Syndrome? It results from an unequal sharing of sex chromosomes soon after fertilization. Patients with Klinefelter syndrome are highly susceptible to psychiatric disturbances as compared to the general population. Klinefelter’s syndrome is the clinical result of an additional X chromosome in males (47,XXY), although other chromosome abnormalities (such as 46,XY/47,XXY mosaicism; 48,XXXY; 49,XXXXY) account for 10-20% of cases.1 2 Classic clinical findings include infertility, small testes, hypergonadotropic hypogonadism (elevated luteinising hormone and follicular stimulating hormone … REVIEW ARTICLE Klinefelter Syndrome The Commonest Form of Hypogonadism, but Often Overlooked or Untreated Eberhard Nieschlag SUMMARY Background: Klinefelter syndrome (KS) with the karyotype 47,XXY is one of the commonest types of congenital chro-mosomal disorder in males, with an incidence of 0.1% to 0.2% of newborn male infants. The classic form (nonmosaic type) of Klinefelter syndrome (KS) is observed in one per 660 births, with up to 3%‐4% occurring in infertile men and 10%‐12% occurring in nonobstructive azoospermia (NOA). Klinefelter syndrome happens when a male is born with an additional X chromosome. 54 In early life, Klinefelter may be diagnosed in boys with behavioral disorders, abnormally small testes, and long legs (Fig. Klinefelter syndrome is largely undiagnosed in the general population. The clinical phenotype of KS was first described in males with tall stature, small testes, gynecomastia, and azoospermia with the genetic etiology of supernumerary X chromosomes identified in 1959. XXY aneuploidy is the most common disorder of sex chromosomes in humans, with prevalence of one in 500 males. Klinefelter syndrome occurs in about 1 out of 500 to 1,000 baby boys. The presence of an extra X chromosome in males with Klinefelter syndrome results in an XXY arrangement; this affects physical and cognitive … Symptoms may include any of the following: Abnormal body proportions (long legs, short trunk, shoulder equal to hip size) … Many people with KS are not diagnosed until they are adults, and it is believed that up to two thirds may never be diagnosed at all. Klinefelter syndrome may adversely affect testicular growth, resulting in smaller than normal testicles, which can lead to lower production of testosterone. Chromosomes are genetic material and males typically have one X and one Y chromosome (XY) and females have two X chromosomes (XX). Klinefelter syndrome, also known as XXY syndrome, is a condition in boys and men that’s caused by an extra X chromosome. These are named either X or Y. The primary features are infertility and small poorly functioning testicles. Professional Reference articles are designed for health professionals to use. It can affect physical and mental development. A mother who gives birth over the age of 40 is two to three times more likely to have a baby with Klinefelter syndrome than a mother who is age 30 at birth. Recent Articles. National Helpline 0300 111 47 48 WebAdmin@ksa-uk.net. Klinefelter’s Syndrome (KS) is a common congenital condition which is found in around 1 in 600 live male births and is caused by the presence of one or more additional sex chromosomes. Some men see themselves as being without any signs related to Klinefelter syndrome, but a physician would be able to find discrete signs related to the syndrome. It results in small testes, testosterone deficiency, infertility and often in swelling of glandular breast tissue (gynecomastia). Klinefelter syndrome occurs when a male receives an extra X sex chromosome. Clin Genet. Klinefelter syndrome is the most common sex chromosome disorder, manifested as hypogonadism, gynecomastia, and impaired spermatogenesis. We offer support and information to all affected by, or having an interest in, Klinefelter’s Syndrome. report the findings of a survey of the current practices of fertility care in adolescent males with Klinefelter syndrome (KS) among members of the Society for the Study of Male Reproduction, the Pediatric Endocrine Society, and the Endocrine Society (overall response rates of 4.7%, 5%, and 1%, respectively). This results in smaller-sized testicles, low testosterone levels, and possibly infertility. Klinefelter syndrome only affects males. The clinical phenotype of KS was first described in males with tall stature, small testes, gynecomastia, and azoospermia with the genetic etiology of supernumerary X chromosomes identified in 1959. A study on the KS prevalence in Japan found a lower prevalence at 60 per 100 000, 2 indicating the presence of racial differences. Klinefelter syndrome (KS), also known as 47,XXY is the set of symptoms that result from two or more X chromosomes in males. Klinefelter syndrome is a genetic condition that results when a boy is born with an extra copy of the X chromosome. It is sometimes just called XXY. Klinefelter syndrome (sometimes called Klinefelter's, KS or XXY) is where boys and men are born with an extra X chromosome. Early identification is helpful in treating and managing Klinefelter syndrome. Klinefelter syndrome can cause problems with learning and sexual development in guys. Following the 1st International Workshop on the Klinefelter Syndrome in 2010 (Juul et al., 2011), the 2nd IWKS took place in Münster, Germany from March 10 to 12, 2016 and was organized by the Centre of Reproductive Medicine and Andrology of the University of Münster. Often, symptoms are subtle and subjects do not realize they are affected. Klinefelter's syndrome is the most common cause of testicular failure that results in impairments in both spermatogenesis and—to a lesser extent—testosterone production. These include personality changes, depression, … Treatment may include: Testosterone replacement: About half of people with … Early recognition and hormonal treatment can improve quality of life and prevent serious complications. Summary. Chromosomes are packages of genes found in every cell in the body. Klinefelter Syndrome. Infertility is the most common symptom of Klinefelter syndrome. This syndrome is the most common sexchromosome disorder affecting 1 in 500 men across all ethnic groups, but the diagnosis is often delayed because of substantial variation in clinical presentation. Testosterone replacement therapy is a mainstay of treatment. Humans normally have two sex chromosomes in each cell—females have two X chromosomes (described as XX), and males have one X and one Y chromosome (described as XY). It's a genetic condition (meaning a person is born with it). When a diagnosis is made, treatment is based on the signs and symptoms present in each person, especially the problems related to hypogonadism, gynecomastia, and psychosocial problems. Until now, however, … Klinefelter syndrome appears to occur more frequently with both older maternal and paternal age (over the age of 35.) However, Klinefelter syndrome is often overlooked or untreated. Treatment and prognosis. Klinefelter syndrome, disorder of the human sex chromosomes that occurs in males, one of the most frequent chromosomal disorders in males. You may find the Klinefelter's Syndrome article more useful, or one of our other health articles. Next Article Klinefelter's syndrome: a late diagnosis. Klinefelter syndrome 47,XXY was first described 70 years ago (1). Klinefelter syndrome is the most common sex chromosome disorder, manifested as hypogonadism, gynecomastia, and impaired spermatogenesis. Klinefelter syndrome (KS) is the most common genetic form of male hypogonadism, but overt phenotype becomes evident only after puberty. Women who get pregnant after age 35 are slightly more likely to have a boy with this syndrome than younger women. Other sex chromosomal aneuploidies have also been described, although they are much less frequent, with … Klinefelter syndrome is the most frequent sex chromosome abnormality and is seen in about 150 boys out of every 100,000 live-born boys. Complications. This may have implications for treatment of Klinefelter's syndrome and suggests that the X chromosome may be involved in the … 16.7). It is characterized by the presence of one or more extra X chromosomes. Signs and symptoms seen in Klinefelter syndrome. Between 1 in 500 and 1 in 1,000 boys are born with Klinefelter's syndrome (KS). Those affected … It causes hypogonadism and infertility. … There are 2 types of chromosome, called the sex chromosomes, that determine the genetic sex of a baby. An interesting XXY story from Glass magazine; Research into men’s experience of pregnancy following fertility treatment; Guy’s Hospital First Klinefelter’s Syndrome (KS/XXY) Adolescent Clinic; Contact the KSA . Because symptoms of Klinefelter syndrome (KS) can sometimes be very mild, many people are never diagnosed or treated. Klinefelter Syndrome affects 1 in 500 male conceptions and is therefore the most common sex chromosome abnormality. Klinefelter syndrome (KS) is the result of 2 or more X chromosomes in a phenotypic male. Here, we report high levels of schizophrenia-spectrum pathology in 32 men with this syndrome in comparison with 26 healthy controls. An extra X sex chromosome X sex chromosome for health professionals to use for mental retardation unknown. 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