The karyotype of a person with klinefelter syndrome is usually 47,xxy, meaning that an individual has 47 autosomes, two x chromosomes, and a y chromosome. Klinefelter syndrome and other sex chromosomal aneuploidies. Klinefelter syndrome ks, also known as 47,xxy or xxy, is the set of symptoms that result from two or more x chromosomes in males. Taking into consideration the findings in xyy and xxxyy individuals, it appears that the addition of a y chromosome to xy, xxy and xxxy complexes has a variable and as yet not clearly delineated harmful effect. Klinefelter syndrome increases the risk of developing extragonadal germ cell tumors and breast cancer.
Seminoma of the testis in a patient with 48, xxyy variant of klinefelter s syndrome. Xxyy syndrome occurs in approximately 118,000 male births. Sep 21, 2019 klinefelter syndrome is a genetic condition affecting males, and it often isnt diagnosed until adulthood. Human cells usually contain two sex chromosomes, one from the mother and one from the father. May 07, 2012 48, xxyy syndrome is a chromosomal condition, characterized by the presence of an extra x and y chromosome in males, that causes medical and behavioral problems.
When in 1942 harry klinefelter and his colleagues described the condition carrying his name 1, its aetiology was unknown. Other sex chromosomal aneuploidies have also been described, although they are much less frequent, with 48, xxyy and 48,xxxy. The primary features are infertility, small testicles and hypogonadism. The primary features are sterility and small testicles. About 20% are variants which include 48, xxyy, 48,xxxy, 49,xxxxy syndromes and. The official parents sourcebook on klinefelter syndrome. A guide for families and individuals affected by extra x and y chromosome variations thanks to the generosity of the book s author, virginia isaacs cover, msw, axys is pleased to make this book available to the x and y variation community, in its entirety, at no cost.
Apr, 2004 the book is designed for physicians, medical students preparing for board examinations, medical researchers, and patients who want to become familiar with research dedicated to klinefelter syndrome. It results from an unequal sharing of sex chromosomes soon after fertilization. There are 2 types of chromosome, called the sex chromosomes, that determine the genetic sex of a baby. Variants of klinefelter syndrome are as followsref32 ref33. Most commonly, affected individuals are taller than average are unable to father biological children infertile. Similar physical phenotype to 47, xxy, but males are taller and have disproportionately longer lower extremities. Another name for klinefelter syndrome, variants or close medical condition association. The xxy condition that causes klinefelter syndrome cant be changed, but medical treatment and working with.
Enter your mobile number or email address below and well send you a link to download the free kindle app. Living with xxy became a nonprofit 501c3 charitable organization on november 6th, 2019. Breast carcinoma in association with the klinefelter syndrome. Klinefelter syndrome, variants symptoms, diagnosis. Other sex chromosomal aneuploidies have also been described, although they are much less frequent, with 48, xxyy. A number of associated anomalies have been observed in the xxyy group, but whether they are of any special significance or merely coincidental remains to be determined table i. The effects of additional x chromosomes are due to hormonal changes, decreased androgen production and increased estrogen levels 4.
Pdf clinical and behavioural profile of a rare variant. The characteristics of the syndrome are discussed, including those signs of interest to dermatology. Klinefelter syndrome, variants is listed as a rare disease by the office of rare diseases ord of the national institutes of health nih. Xxyy is still considered a variation of klinefelter syndrome by some definitions, mainly because the pathophysiology of the testicular dysfunction has not been shown to differ from 47, xxy, and the most current research does not suggest that there should be any differences in the evaluation and treatment of testosterone deficiency in 48, xxyy compared to 47, xxy.
Variants of the disease with three, four, or more extra. Klinefelter s syndrome often goes undiagnosed in affected males. Klinefelter syndrome symptoms and causes mayo clinic. Review article klinefelter syndrome the commonest form of hypogonadism, but often overlooked or untreated eberhard nieschlag summary background. Sometimes, symptoms are more prominent and may include. Klinefelter syndrome with xyxxy mosaic klinefelters.
A genetic condition where males have at least one extra x chromosome or extra copies of both the x and y chromosomes in each cell. Klinefelter syndrome ks with the karyotype 47,xxy is one of the commonest types of congenital chromosomal disorder in males, with an incidence of 0. Klinefelter syndrome genetic and rare diseases information. Nondisjunction of sex chromosomes during maternal meiosis 53% or paternal meiosis 47% results in 47, xxy genotype classically, although variants such as xxyy, xxxy, and xxxxy, and mosaic patterns, such as xxxxy, also exist. People typically have 46 chromosomes in each cell, two of which are the sex chromosomes. Living with klinefelter syndrome, trisomy x, and 47, xyy.
The primary features are infertility and small poorly functioning testicles. In 1959, these men with klinefelter syndrome were discovered to have an extra x chromosome genotype xxy instead of the usual male sex complement genotype xy. Below are some links for more information for those who have one of these variants or a friend or family member with these rarer variants of klinefelter syndrome. Entry version abbreviation entry terms 48, xxyy syndrome add 49,xxxxy syndrome add klinefelter syndrome add klinefelter syndrome, variants add. Klinefelter syndrome definition, symptoms, treatment. Klinefelter syndrome a medical dictionary, bibliography.
Often, symptoms may be subtle and many people do not realize they are affected. Acta androgen aneuploidy associated bandmann e breit barr barr bodies basal biopsy bone formation boys with klinefelter s breast cancer chromatinpositive chromosome anomaly clin endocrinol metab clinical controls cytogenetic decreased dermatoglyphic diagnosis drome effect estrogen eunuchoid excretion f x sw felter s syndrome female ferguson. Klinefelter syndrome ks also known as 47, xxy or xxy, is the set of symptoms that result from two or more x chromosomes in males. Variants of this syndrome with x and y polygamy are of rare occurrence. Females have two x chromosomes 46,xx, and males have one x and one y chromosome 46,xy. Other frequent variants include 48, xxxy, 49, xxxxy, and 48, xxyy 5 6. It affects between 1 in 500 and 1 in 1,000 newborn males. Although this site implies xyy is a variant of klinefelter s syndrome, it is not, as xyys do not have atrophied testes, therefore do not have seminiferous tubule dysgenesis, which you can read. First, you will not waste time searching the internet while missing a lot of relevant information. Ever since, diagnosing klinefelter s syndrome has required the demonstration of the 47, xxy karyotype or one of its rare variants.
Therefore, you should understand that klinefelter syndrome is often considered a synonym or a condition closely related to the following. Klinefelter syndrome ks is a sex chromosomal anomaly, which in most cases is characterized by 47 chromosomes instead of the usual 46. Instead of having the usual xy chromosome pattern that most males have, these men have an xxy pattern. April 9, 2011 sex chromosome tetrasomy and pentasomy conditions occur in 1. Taking into consideration the findings in xyy and xxxyy individuals, it appears that the addition of a y chromosome to xy, xxy and xxxy complexes has a. Xy47, xxy mosiac, chromosome 48 xxxy, chromosome 48 xxyy, chromosome xxy, hypergonadotropic hypogonadism, primary hypogonadism, seminiferous tubule dysgenesis, xxy syndrome. Chromosomes are packages of genes found in every cell in the body. Patients with 48, xxyy tend to be taller and more aggressive than those with 47,xxy klinefelter syndrome. Autism spectrum disorder in males with sex chromosome. Xxy syndrome, 47, xxy males, epidemiology of klinefelter s syndrome 1. Klinefelter syndrome ks, also known as 47, xxy is the set of symptoms that result from two or more x chromosomes in males. 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. Rare case of klinefelters syndrome with 48xxyy vasudev magaji md, debra feden crnp and gretchen perilli, md references.
Xxyy syndrome is a sex chromosome anomaly in which males have an extra x and y chromosome. Handbook of genetic counselingklinefelter syndrome. Individuals with 48, xxyy are usually considerably tall with small testes that do not function normally leading to infertility. They include variations in body hair, lack of acne at adolescence, multiple cutaneous angiomas, acrocyanosis, and. Klinefelter syndrome is a chromosomal condition in boys and men that can affect physical and intellectual development. Sometimes, symptoms are more prominent and may include weaker muscles, greater height, poor coordination, less. An xxyy variant of the klinefelter syndrome in a prepubertal. Clinically, it is not clearly distinct from the more com mon xxy type of the klinefelter individual. Similar physical phenotype to 47,xxy, but males are taller and have disproportionately longer lower extremities. Klinefelter syndrome ks is a common genetic condition, affecting one in 450 men. Mar 23, 2020 in 1942, klinefelter et al published a report on 9 men who had enlarged breasts, sparse facial and body hair, small testes, and an inability to produce sperm. In recent years, many males have been diagnosed with klinefelter syndrome before birth, through amniocentesis or chorionic villus sampling cvs. An xxyy variant of the klinefelter syndrome in a prepubertal boy is described. What are the genetic variants of klinefelter syndrome.
Klinefelter syndrome is a fairly common genetic condition found in males only. There have been reports of an even more extreme variant of klinefelters syndrome mosaic in newborn males duenas et al. This is the most rare of the klinefelters syndrome variants and has been reported in over one hundred cases with the frequency being approximately 1 in 85,000 newborn males duenas et al. Xxyy is sometimes considered a variant of another syndrome called klinefelter syndrome, or 47, xxy. Two of the 46 chromosomes, known as x and y, are called sex chromosomes because they help determine whether a person will develop male or female sex characteristics. Klinefelter syndrome for parents nemours kidshealth. Dec 23, 2015 rarely, an individual may possess both an additional x and an additional y chromosome 48, xxyy. Feb 08, 1974 the xxyy variant of klinefelter s syndrome author s transl. Feb 14, 2018 klinefelter syndrome ks is a condition that occurs in males when they have an extra x chromosome. There have been reports of an even more extreme variant of klinefelter s syndrome mosaic in newborn males duenas et al. Syndrome definition in medicine and psychology, a syndrome is the association of several clinically recognizable features, signs observed by someone other than the patient, symptoms reported by the patient, phenomena or characteristics that often occur together, so that the presence of one or more.
The condition is not inherited but is a result of problems during cell division. Patients typically have intellectual challenges iq range 6080, delayed speech, learning disabilities. Five individuals with a variant of klinefelter s xxyy syndrome are presented. Its seeming rarity may be ascribed to the subtleties of clinical manifestation in a prepubertal boy rather than difficulty in establishing the diagnosis once suspected. There are other types of sex chromosome anomalies such as xyy, xxxy, xxxxy, and variations in girls such as xo turner syndrome, xxx, xxxx. This is the most rare of the klinefelter s syndrome variants and has been reported in over one hundred cases with the frequency being approximately 1 in 85,000 newborn males duenas et al. Klinefelter s syndrome is a sex chromosomal aneuploidy caused by an addition of x chromosome in males 47, xxy. These patients, together with five xxyy subjects recorded in the literature, show the clinical features of klinefelter s syndrome.
Section of neurodevelopmental behavioral pediatrics, department of pediatrics, university of colorado school of medicine, aurora, co, usa. If you have any recommendations for sites that have helped you, please feel free to let me know and i will be glad to add to the resources below. Klinefelter syndrome, disorder of the human sex chromosomes that occurs in males, one of the most frequent chromosomal disorders in males. Apr 14, 20 professor rob mclachlan discusses klinefelter syndrome, and how it can present differently in each individual but a common feature is that all men with klinefelter syndrome will have small testes. More than 60 patients with 48, xxyy complement have been reported since the first case was published by muldal and ockey 99 in 1960. Normally male cells contain one x and one y chromosome in each cell. A fifthdigit clinodactyly and nail biting, b prominent elbows with hyperextensibility and c lower extremities with low muscle bulk in the calves, flat feet and mild pronation at the ankles. Reviewarticle 48, xxyy, 48,xxxyand 49,xxxxy syndromes.
Many boys with klinefelter syndrome also known as xxy syndrome have no signs or symptoms, and some dont even know they have it until later in life. May 03, 2020 and klinefelter s syndrome, which is the symptoms of low testosterone in xxy and variant males, called seminiferous tubule dysgenesis, has nothing at all to do with anything but hypogonadism. Variants of 48xxxy and 48xxyy klinefelter syndrome. The appearance of at least one y chromosome with a properly. Its seeming rarity may be ascribed to the subtleties of clinical manifestation in a prepubertal boy rather than dieulty in establishing the diagnosis once suspected. Learn more about the causes, symptoms, and treatment of klinefelter syndrome. This means that klinefelter syndrome, variants, or a subtype of klinefelter syndrome, variants, affects less than 200,000 people in the us population. Sometimes, symptoms are more prominent and may include weaker muscles, greater height, poor. A guide for families and individuals affected by x and y chromosome variations cover msw, virginia isaacs on.
Klinefelter syndrome sometimes called klinefelter s, ks or xxy is where boys and men are born with an extra x chromosome. Article in german hornstein op, rott hd, schwanitz g, grosse g. Klinefelter syndrome mesh descriptor data 2020 mesh. Klinefelter syndrome xxy, xyy, xxx, xxyy, xxxy, xxxxy and associated variants. Photograph of physical features in xxyy, xxxy and xxxxy including. Usually, females have two x chromosomes xx and males have one x and one y chromosome xy.
Oct 24, 2006 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. Xxy aneuploidy is the most common disorder of sex chromosomes in humans, with prevalence of one in 500 males. The most common sex chromosomal aneuploidy in males is klinefelter syndrome, with the prevalence of 1. The most common variant is 47, xxy which accounts for 90% of klinefelter syndrome cases 4 6. It is the most common sex chromosome disorder, affecting 1 in 660 men. Most often, boys and men with klinefelter syndrome. In 1959 jacobs and strong 2 recognized the chromosomal basis of the disorder, until then solely defined through a set of clinical criteria. Klinefelter syndrome may adversely affect testicular growth, resulting in smaller than normal testicles, which can lead to lower production of testosterone.
Some males with ks have no obvious signs or symptoms while others may have varying degrees of cognitive, social, behavioral, and learning difficulties. The 48, xxyy syndrome is generally considered the most common variant of the klinefelter syndrome 47,xxy. The xxyy variant of klinefelters syndrome authors transl. Xxyy syndrome is the name attached to the cluster of symptoms that arise as a result of the 48, xxyy chromosome pattern. We aim to increase awareness and inform the health and education sectors and broader community. Klinefelter syndrome and its variants are the most common forms of sex chromosome aneuploidy, with a reported incidence of 1 in 500 to 1 in live births. The most common variant of klinefelter syndrome similar physical phenotype to 47, xxy, but males are taller and have disproportionately longer lower extremities iq is typically reduced and ranges from 60 to 80. Originally described as a variant of klinefelter syndrome xxy because of shared features of tall stature and hypogonadism,22 it is now recognized that xxyy is associated with more significant cognitive deficits and behavioral disorders, as well as a higher rate of. Klinefelter syndrome, also known as the xxy condition, is a term used to describe males who have an extra x chromosome in most of their cells. Browse az genetic and rare diseases information center. While often compared with 47, xxy klinefelter syndrome.