Klinefelter syndrome (KS) is the result of 2 or more X chromosomes in a phenotypic male. Complications. 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 … 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. 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. Those affected … You may find the Klinefelter's Syndrome article more useful, or one of our other health articles. 2002;61:49–53. Klinefelter Syndrome affects 1 in 500 male conceptions and is therefore the most common sex chromosome abnormality. Other sex chromosomal aneuploidies have also been described, although they are much less frequent, with … Recent Articles. Klinefelter syndrome (sometimes called Klinefelter's, KS or XXY) is where boys and men are born with an extra X chromosome. Klinefelter's syndrome, characterised by a 47, XXY chromosomal pattern, has largely been associated with physical abnormalities. Affected males have an extra X chromosome. 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. Professional Reference articles are designed for health professionals to use. This results in smaller-sized testicles, low testosterone levels, and possibly infertility. Summary. Until now, however, … Clin Genet. Klinefelter syndrome is the most common sex chromosome disorder, manifested as hypogonadism, gynecomastia, and impaired spermatogenesis. Klinefelter's syndrome is a genetic condition that only affects males. Klinefelter syndrome, disorder of the human sex chromosomes that occurs in males, one of the most frequent chromosomal disorders in males. It results in small testes, testosterone deficiency, infertility and often in swelling of glandular breast tissue (gynecomastia). Testosterone replacement is mainly for androgen deficiency but does not improve infertility 7. 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. increased incidence of male breast malignancy; increased incidence of germ cell … Klinefelter syndrome (KS) is the most common genetic form of male hypogonadism, but overt phenotype becomes evident only after puberty. Treatment may include: Testosterone replacement: About half of people with … It can affect physical and mental development. Signs and symptoms seen in Klinefelter syndrome. It results from an unequal sharing of sex chromosomes soon after fertilization. It is characterized by the presence of one or more extra X chromosomes. We offer support and information to all affected by, or having an interest in, Klinefelter’s Syndrome. Chromosomes are genetic material and males typically have one X and one Y chromosome (XY) and females have two X chromosomes (XX). 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). 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. Klinefelter syndrome, also known as XXY syndrome, is a condition in boys and men that’s caused by an extra X chromosome. Here, we report high levels of schizophrenia-spectrum pathology in 32 men with this syndrome in comparison with 26 healthy controls. Klinefelter syndrome is a genetic condition affecting males, and it often isn't diagnosed until adulthood. 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. They are written by UK doctors and based on research evidence, UK and European Guidelines. National Helpline 0300 111 47 48 WebAdmin@ksa-uk.net. 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 occurs when a male receives an extra X sex chromosome. Signs and symptoms vary greatly. Testosterone replacement therapy is a mainstay of treatment. These are named either X or Y. Treatment and prognosis. 16.7). The presence of only long lower extremities distinguishes Klinefelter syndrome from the other forms of eunuchoidism that results in equally long upper and lower extremities. 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. The term Klinefelter syndrome (KS) describes a group of chromosomal disorder in which there is at least one extra X chromosome to a normal male karyotype, 46,XY. Article Translations: What Is Klinefelter Syndrome? The presence of an extra X chromosome in males with Klinefelter syndrome results in an XXY arrangement; this affects physical and cognitive … Chromosomes are packages of genes found in every cell in the body. Symptoms. 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). Klinefelter syndrome is a common cause for mental retardation of unknown etiology among prepubertal males. Klinefelter Syndrome. 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. It is characterized by the presence of one or more extra X chromosomes. Klinefelter syndrome may adversely affect testicular growth, resulting in smaller than normal testicles, which can lead to lower production of testosterone. Patients with Klinefelter syndrome are highly susceptible to psychiatric disturbances as compared to the general population. In this issue of the Journal, Zganjar et al. However, Klinefelter syndrome is often overlooked or untreated. Klinefelter syndrome can cause problems with learning and sexual development in guys. 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. Next Article Klinefelter's syndrome: a late diagnosis. Klinefelter syndrome occurs in about 1 out of 500 to 1,000 baby boys. Between 1 in 500 and 1 in 1,000 boys are born with Klinefelter's syndrome (KS). Learn more about the causes, symptoms, and treatment of Klinefelter syndrome. Klinefelter syndrome 47,XXY was first described 70 years ago (1). 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. 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. XXY aneuploidy is the most common disorder of sex chromosomes in humans, with prevalence of one in 500 males. This may have implications for treatment of Klinefelter's syndrome and suggests that the X chromosome may be involved in the … Klinefelter syndrome (KS) is the result of 2 or more X chromosomes in a phenotypic male. Patients with Klinefelter syndrome are highly susceptible to psychiatric disturbances as compared to the general population. With an incidence of 0.1% to 0.2% of male neonates (i.e. Because symptoms of Klinefelter syndrome (KS) can sometimes be very mild, many people are never diagnosed or treated. Klinefelter syndrome is the most frequent sex chromosome abnormality and is seen in about 150 boys out of every 100,000 live-born boys. Early recognition and hormonal treatment can improve quality of life and prevent serious complications. Klinefelter syndrome only affects males. It causes hypogonadism and infertility. It's a genetic condition (meaning a person is born with it). 54 In early life, Klinefelter may be diagnosed in boys with behavioral disorders, abnormally small testes, and long legs (Fig. There are 2 types of chromosome, called the sex chromosomes, that determine the genetic sex of a baby. Early identification is helpful in treating and managing Klinefelter syndrome. Klinefelter syndrome is largely undiagnosed in the general population. 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. 9. Symptoms may include any of the following: Abnormal body proportions (long legs, short trunk, shoulder equal to hip size) … These include personality changes, depression, … Klinefelter syndrome is a genetic condition that results when a boy is born with an extra copy of the X chromosome. The primary features are infertility and small poorly functioning testicles. Infertility is the most common symptom of Klinefelter syndrome. These include personality changes, depression, and psychosis. Klinefelter syndrome happens when a male is born with an additional X chromosome. Klinefelter syndrome appears to occur more frequently with both older maternal and paternal age (over the age of 35.) It is sometimes just called XXY. 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). Often, symptoms are subtle and subjects do not realize they are affected. 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