Dec 01, 2020 klinefelter syndrome ks is defined as the presence of one or more extra x chromosome in a male patient. In february 2010 an interdisciplinary panel of specialists met in abano terme padua, italy in a workshop on klinefelter syndrome. Neonatal klinefelters syndrome jama pediatrics jama network. This condition may lead to various medical problems, which may include. Since it has a wide spectrum of clinical manifestations, which. For example, some genes determine height and hair color. Klinefelter syndrome ks, also known as 47,xxy is the set of symptoms that result from two or more x chromosomes in males. Pdf klinefelter syndromea clinical update researchgate. Apr 01, 2011 klinefelter syndrome ks was first described by harry f. Clinical features of klinefelter syndrome groth k et al.
On the basis of patient registries in denmark, it is suspected that only 25% of all klinefelter syndrome patients are diagnosed during their lifetimes 8. Pdf klinefelter syndrome in clinical practice claus. Klinefelter syndrome ks is the leading genetic cause of primary hypogonadism and infertility in men. Affected men are infertile as a consequence of azoospermia caused by sclerosed seminiferous tubules. Jan 01, 20 klinefelter syndrome, 47,xxy ks, occurs in about 150 per 100,000 males and is the most frequent chromosomal aberration in males. Different clinical presentation of klinefelters syndrome in. Mar 23, 2020 klinefelter syndrome may be diagnosed prenatally from fetal cytogenetic analyses performed on chorionic villi or amniocytes. Dec 01, 2005 klinefelter syndrome is a numerical chromosome abnormality in males, characterized by the presence of one or more extra x chromosomes.
Klinefelter syndrome american academy of family physicians. Klinefelter syndrome is a chromosomal condition in boys and men that can. Klinefelter syndrome is a genetic condition in which boys are born with an extra copy of the x chromosome xxy. Consensus statement on diagnosis and clinical management. In 1959, these men with klinefelter syndrome ks were discovered to have an extra x chromosome.
Plasma testosterone, folliclestimulating hormone fsh, and luteinizing hormone lh values in healthy control subjects and patients with klinefelter syndrome ks. One of these is the shox short stature homeboxcontaining gene, which is responsible for the short stature characteristic of turners syndrome 45,x0 ellison et al. These findings should guide future research and highlight the importance of establishing clinical practice guidelines. There is a lack of data supporting best practices for ks patients care.
Prenatal and postnatal prevalence of klinefelter syndrome. On the basis of chromosome analysis, 85 patients group i were diagnosed as having klinefelter syndrome, and 224 patients had a 46,xy karyotype group ii. Pdf klinefelter syndrome is the most common sexchromosome disorder. Klinefelter syndrome is a group of conditions affecting the health of males who are born with at least one extra x chromosome. Clinical klinefelter syndrome a eneral ractice ersectie 40 reprinted from australian family physician vol. Nevertheless, suspected klinefelter syndrome is easy to diagnose if physicians know the syndrome and thorough clinical examination is performed. Genetic diagnostics of male infertility in clinical practice. If klinefelter syndrome is not diagnosed prenatally, a patient with 47,xxy karyotype may demonstrate various subtle, agerelated clinical signs that would prompt diagnostic testing. Genes provide specific instructions for body characteristics and functions. This aneuploidy results in a variety of phenotypes, including hypogonadism, androgen deficiency and infertility lanfranco et al, 2004. Xxy definition klinefelter syndrome is a chromosomal disorder that affects only males.
Dec 01, 2016 the nhgri maintains an information page, learning about klinefelter syndrome. Characteristic clinical findings infertility azoospermia or oligospermia small, firm testes hypergonadotropic hypogonadism gynecomastia tall, slender body habitus with long. During the program, talks were presented by leading researchers in the field followed by lively discussions among the 120. Physical manifestations of this syndrome develop at puberty. Clinical and diagnostic features of patients with suspected. Feb 14, 2005 clinical care issues klinefelter syndrome the diagnosis of klinefelter syndrome is based on the presence of at least one extra x chromosome, in the presence of a y chromosome. Neonatal klinefelters syndrome jama pediatrics jama.
Reproductive medicine, university of amsterdam, amsterdam, the netherlands. There are approximately 250,000 men with ks in the united states, and the prevalence of ks in male reproductive practices is 3 to 4%. Fertility considerations in adolescent klinefelter syndrome. Recently, new clinically important information regarding klinefelter syndrome ks has been published. Klinefelter syndrome ks is the most common genetic form of male hypogonadism, but overt phenotype becomes evident only after puberty. Intriguingly, whereas male secondary sexual deficiency is normally reversible by androgen repla cement therapy in klinefelter patients, their infertility is intractable. Clinical studies hitherto conducted with a focus on testosterone substitution therapy in men with hypogonadism did not indicate an increased malignization rate of prostate tissue 26. Klinefelter syndrome in clinical practice researchgate. Variation in clinical presentation and insufficient awareness of this syndrome among clinicians lead to fifty percent of. Treatment of ks can also benefit from the input of healthcare providers. Klinefelter syndrome is the most common sex chromosome disorder in males.
The syndrome was first identified and described in 1942 by harry fitch klinefelter jr. Fertility preservation practices in adolescents with klinefelter syndrome vary greatly within and among the specialties caring for these patients. Typically small, soft testes with underdeveloped secondary sex characteristics, such as sparse facial and body hair. The prototypic man with klinefelter syndrome has traditionally been described as tall, with narrow shoulders, broad hips, sparse body hair, gynecomastia, small. People with this condition are born with at least one extra x chromosome. Assessing the risks and benefits of diagnosing genetic conditions with variable phenotypes through population screening. Ks is the most common sex chromosome disorder in males, affecting one in 660 men.
Following the 1st international workshop on the klinefelter syndrome in 2010 juul et al. Fertility in adolescents with klinefelter syndrome. It is characterised by an additional x chromosome, leading to the 47,xxy karyotype. The first clinical description of men presenting with bilateral gynecomastia, small testes, aspermatogenesis, reduced leydig cell function and increased excretion of follicle. Klinefelter syndrome i n clinical practice anders bojesen and claus h gravholt introduction in 1942, harry f klinefelter, edward c reifenstein and fuller albright described nine patients with. Clinical manifestations of klinefelter s syndrome are determined by genes that are not inactivated in the extra x chromosome. Klinefelter syndrome is the most common sexchromosome disorder. Klinefelter syndrome, we evaluated the clinical symptoms as well as the diagnostic value of the barr body test for screening procedures. Klinefelters syndrome karyotype 47, xxy and schizophrenia. Some patients may exhibit all of the classic signs of this disorder, including gynecomastia, small testes, sparse body hair, tallness, and infertility, whereas others, because of the. Mortality in patients with klinefelter syndrome in britain. The structural abnormalities of the testes of the neonate with klinefelter s syndrome 47, xxy. The genetic origin of klinefelter syndrome and its effect on.
Although first identified over 70 years ago, klinefelter syndrome ks continues to pose substantial diagnostic challenges, as many patients are still misdiagnosed, or remain undiagnosed. Klinefelter syndrome ks is the most frequent sex chromosomal anomaly in males and denotes a karyotype 47,xxy. Bojesen a, gravholt ch 2007 klinefelter syndrome in clinical practice. Apr 11, 2014 nearly 70 years after its description, klinefelter syndrome ks remains a largely undiagnosed condition. Medical management of klinefelter syndrome xxy in adults. In conjunction with the clinical trials it conducts, the nichd provides counseling and research for patients with suspected or diagnosed genetic disorders.
Often, symptoms are subtle and subjects do not realize they are affected. During childhood, and even during early puberty, pituitarygonadal function in 47,xxy subjects is relatively normal, but from midpuberty onwards, fsh and lh levels increase to hypergonadotropic levels, inhibin b decreases to undetectable levels, and. In 1942, harry f klinefelter, edward c reifenstein and fuller. Klinefelter in 1942 as a clinical entity characterized by gynecomastia, small testes, absent spermatogenesis, normal to moderately reduced leydig cell function, and increased secretion of fsh. Vo2 max, the maximum capacity to transport and utilize oxygen during incremental exercise. The primary features are infertility and small poorly functioning testicles. Klinefelter syndrome ks is the most frequent chromosome disorder in. Classic characteristics of ks include small testes, infertility. Because knowledge of klinefelter syndrome can only be derived.
Whereas fsh and lh levels seen in ks are in most cases well above normal, there is a large degree of overlap in total plasma. Some males with ks have no obvious signs or symptoms while others may have varying degrees of cognitive, social, behavioral, and learning difficulties. Different clinical presentation of klinefelters syndrome. The original clinical presentation of klinefelter s syndrome was described by klinefelter s, reifenstein, and albright in 1942, who reported 9 adult males with gynecomastia, small and firm testes, azoospermia, and elevation of serum fsh with functional leydig, cells. As its clinical presentation may be subtle, many of those affected may be unaware or diagnosed only during evaluation for hypogonadism andor infertility. Fertility considerations in adolescent klinefelter. At the mass general hospital klinefelter syndrome clinic, we aim to provide high quality, coordinated care to individuals of all ages living with klinefelter. Figure 2 the vicious circle of hypogonadism, abdominal adiposity and insulin resistance has direct and indirect consequences. Solid arrows indicate promotion, dotted arrows indicate inhibition. Klinefelter syndrome diagnosis and treatment mayo clinic. Ofthe120workshopparticipants,onlyalanrogol and eberhard nieschlag had met harry klinefelter in person, the former as one of his medical teachers at john hopkins in balti. Klinefelter syndrome happens when a male is born with an additional.
Sometimes, symptoms are more evident and may include weaker muscles, greater height, poor coordination, less body hair. It affects approximately 1 in 600 newborn males and the most common chromosomal abnormality, leading to male hypogonadism and infertility. Dec 01, 2009 klinefelter syndrome is a group of conditions affecting the health of males who are born with at least one extra x chromosome. A more recent concern arises from the practice that some men with klinefelter syndrome are nowadays treated with longterm testosterone substitutions. In fact, as few as 25% of patients with ks are accurately diagnosed and most of these diagnoses are not made until adulthood. Ofthe120workshopparticipants,onlyalanrogol and eberhard nieschlag had met harry klinefelter in person, the former as.
Klinefelter syndrome clinic massachusetts general hospital. Consensus statement on diagnosis and clinical management of. This genetic disorder occurs when a male is born with an extra copy of the x chromosome and may result in low testosterone production and. Figure 2 from klinefelter syndrome in clinical practice. Klinefelter syndrome a clinical update j clin endocrinol metab, 98 1 20, pp. The clinical syndrome was initially described in 1942, and the chromosome constitution was discovered in 1959. Klinefelter syndromea clinical update the journal of. Some patients may exhibit all of the classic signs of this disorder, including gynecomastia, small testes, sparse body hair, tallness, and infertility, whereas others, because of the wide. Klinefelter syndrome is the most common sex chromosome disorder. This syndrome is characterized by the presence of one or more extra x chromosomes, and the karyotype 47,xxy.
Abstract klinefelter syndrome ks is the most frequent sex. Klinefelter syndrome ks is the most common chromosomal aberration in men. Patients and their families receive comprehensive evaluations, counseling, and risk assessment. Chromosomes, found in all body cells, contain genes. Herlihy as, mclachlan ri, gillam l, cock ml, collins v, halliday jl. Affected males carry an additional x chromosome, which results in male hypogonadism, androgen deficiency, and impaired spermatogenesis. Ks has a genetic background, with characteristics involving numerous. Klinefelter syndrome ks is a sex chromosomal syndrome in males. Klinefelter syndrome ks is the most common sex chromosome disorder causing primary hypogonadism in males, affecting 1 in 660 men. The most common form of klinefelter syndrome is due to a 47,xxy karyotype and is found in about 80% of cases, but can also be due to variant karyotypes. It was first described in 1942, with a number of additional conditions, characteristics, and abnormalities described in later publications. Infertility considerations in klinefelter syndrome. Nov 01, 2012 klinefelter syndrome ks is the most common sex chromosome disorder causing primary hypogonadism in males, affecting 1 in 660 men. Klinefelter syndrome, spermatogenesis, meiosis, sperm.
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