During the next few years, several major chromosomal syndromes with altered numbers of chromosomes were reported, i. They can have normal sex lives, but they usually make little or no sperm. Instead of having the usual xy chromosome pattern that most males have, these men have an xxy pattern. Klinefelter syndrome is the first human sex chromosomal abnormality to be reported. A chromosomal anomaly with chromosome count 47, xxy sex chromosome constitution. In this system, the sex of an individual is determined by a pair of sex chromosomes. There are enough problems to be had when a person lacks a chromosome that has a complete compliment. The x chromosome was named for its unique properties by early researchers, which resulted in the naming of its. People typically have 46 chromosomes in each cell, two of which are the sex chromosomes.
Nonhodgkins lymphoma and klinefelter syndrome request pdf. People with 47, xxy have two x chromosomes and one y chromosome. Downsyndrome trisomy21, turner syndrome 45,x and klinefelter syndrome 47. Klinefelter syndrome and other sex chromosomal aneuploidies. The country to go to to take such a poll would be d. Whether you are a male or female depends on the presence or absence of certain chromosomes. An xx egg is produced, which when fertilized with a y sperm, yields an xxy offspring. Xxyy syndrome definition of xxyy syndrome by medical.
Only the x chromosome is paired with a homologous match in human females. At first blush, the issue should be fairly straightforward. A variant klinefelter syndrome patient with an xxyxxxy. They may include being taller than average, acne, and an increased risk of learning problems. 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. Numerous studies show xxy boys and men possess the same capabilities as xy boys and men. Klinefelters syndrome ks is the constellation of symptoms associated with an extra sex chromosome, the 47, xxy karotype, compared to the usual male configuration, xy. Sometimes, symptoms are more prominent and may include weaker muscles, greater height, poor coordination, less. The sex chromosome trisomy mouse model of xxy and xyy.
Other sex chromosomal aneuploidies have also been described, although they. Social function in multiple x and y chromosome disorders. One of the challenges of 47,xxy is that it is not characterized by any prominent physical features. Males who carry an extra y chromosome are also tall, averaging 63.
Klinefelter syndrome may adversely affect testicular growth, resulting in smaller than normal testicles, which can lead to. The patient had female external genitalia, clitoromegaly, remnants of the ductus mesonephricus, uterus, and gonads in the labia majora which were determined to be testes by histology. The primary features are infertility and small poorly functioning testicles. An estimated 1 in 500 males has an extra x chromosome. Apr 16, 20 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. Nondisjunction occurs when sister chromatids on the sex chromosome, in this case an x and an x, fail to separate. Klinefelter syndrome, with the karyotype 47,xxy, is one of the commonest types of congenital chromosomal disorder.
Men with xyy syndrome inherit an extra y chromosometheir genotype is xyy. Klinefelter syndrome is a condition in which males have an extra x sex chromosome. Nov 12, 2009 if a man has xx chromosomes it has to be with a y chromosome xxy. Are xyy males more prone to aggressive behavior than xy males. Men with an additional y chromosome 47,xyy exhibit physical and behavioral features that may be a consequence of increased y gene dosage. The controversy over south african athlete caster semenyas gender has given the public a view into the complexities of gender. The xxy condition that causes klinefelter syndrome cant be changed, but medical treatment and working with. This group of symptoms, which include gynecomastia, increased height, sparse facial and body hair, reduced sperm count, and diminutive testicular size, was originally observed. Xxyy syndrome definition of xxyy syndrome by medical dictionary. Females typically have two of the same kind of sex chromosome xx, and are called the homogametic sex. The girl has the normal chromosome count 46 and should be male.
Males are tall and have developmental abnormalities, incoordination. Patients with a 47, xxy karyotype klinefelter syndrome appear to have an increased risk of developing a malignancy in adulthood, usually cancer of the breast, extragonadal germ cell tumor, and. Pgd in 47,xxy klinefelters syndrome patients citeseerx. Klinefelter syndrome definition klinefelter syndrome is a chromosomal disorder that affects only males.
The person is generally otherwise normal, including normal fertility the condition is generally not inherited from a persons parents but rather occurs as a result of a. Klinefelter syndrome for parents nemours kidshealth. The sex chromosome trisomy sct model produces xxy, xyy, xy, and xx mice, each genotype with either testes or ovaries, all within the same litters. Females usually have two x chromosomes 46, xx and males usually have one x and one y chromosome 46, xy.
Male sex chromosome abnormalities klinefelter syndrome males inherit one or more extra x chromosomestheir genotype is xxy or more rarely xxxy or xyxxy mosaic. What percentage of persons with xxy syndrome selfidentify. Human cells contain 23 pairs of chromosomes for a total of 46. Human cells usually contain two sex chromosomes, one from the mother and one from the father. Oct 18, 2017 people with 47, xxy have an extra chromosome.
This group of symptoms, which include gynecomastia, increased height, sparse facial and body hair, reduced sperm count, and diminutive testicular size, was originally observed in nine patients by. About 47,xxy the association for x and y chromosome variations. Among the variant klinefelter genotypes are such karyotypes as xyxxy and xxxxy. Often, symptoms may be subtle and many people do not realize they are affected. To this statement by 1 particularly ignorant xxy man in australia i made this reply. Xyy syndrome is a genetic condition in which a male has an extra y chromosome.
Klinefelter syndrome ks, also known as 47, xxy is the set of symptoms that result from two or more x chromosomes in males. What percentage of persons with xxy syndrome selfidentify as. What happens if someone has an xxy chromosome or an xyy. The x chromosome is one of the two sexdetermining chromosomes in many organisms, including mammals the other is the y chromosome, and is found in both males and females. Males with klinefelter syndrome typically have one extra copy of the x chromosome in each cell, for a total of two x chromosomes and one y chromosome 47, xxy. Some people with 47, xxy may have no noticeable signs or symptoms. Clinical, endocrinological, and epigenetic features of the 46,xx male syndrome, compared with 47,xxy klinefelter patients. Xyy syndrome nord national organization for rare disorders. However, unlike those with klinefelter syndrome xxy, those with xyy syndrome often have macrocephaly and macroorchidism a large head and large testes, but otherwise normal secondary male sexual characteristics, and prominent acne in adolescence. It is less common for affected males to have two or three extra x chromosomes 48,xxxy or 49,xxxxy or extra copies of both the x and y chromosomes 48,xxyy in each cell. As a result of the extra y chromosome, each cell has a total of 47 chromosomes instead of the usual 46. This means he has klinefelter syndrome and does not mean he is gay.
They usually dont make as much testosterone as other boys. Flawed studies although some studies suggest and many researchers imply that xyy are more violent and less intelligent than normal males and, as a result, are more often institutionalized in mental hospitals and prisons, the best exploration of xyy male aggressive behavior looks only at measurable aggressive tendencies, not at end points such as criminal acts of violence and incarceration rates. Usually, females have two x chromosomes xx and males have one x and one y chromosome xy. About one of every 500 males has an extra x chromosome, but many dont have any symptoms.
Only the y chromosome is always found without a homologous match. It is unclear why an extra copy of the y chromosome is associated with tall stature, learning problems, and other features in some. In severe cases, t hey have relatively highpitched voices, asexual to feminine body contours as well as breast enlargement, and comparatively little facial and body hair. In some ways, it is the opposite of klinefelter syndrome. Klinefelter syndrome is a genetic condition that results when a boy is born with an extra copy of the x chromosome.
Effects of sex chromosome aneuploidy on male sexual behavior. 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. Females cannot have klinefelter syndrome they do not have a y chromosome one of the chromosomes responsible for male sexual development. Protein formation cell membrane diffusion immune system chromosome, hemoglobin, sperm, nerve cell, microvilli. Some people with 47, xxy may have no noticeable signs or symptoms features or only mild features. 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. Aug 10, 2016 48,xxxy syndrome is a type of chromosome abnormality characterized by the presence of 2 extra x chromosomes in males. Xxy chromosomes are a naturally occurring human male variation.
Xxy abnormal complement of sex hormones in a male resulting in klinefelters syndrome sex chromosome a chromosome that determines the sex of an. Genetic information is coded onto every chromosome. There are a specific set of characteristics that go along with it, tall stature, less body hair, small testicles, infertil. Klinefelter syndrome, also known as xxy, is a genetic disorder affecting males from birth. A sevenyearold girl with a y chromosome is providing new clues about a possible master switch of maleness. About 47,xxy klinefelter syndrome 47,xxy is the most common of the x and y variations, also known as sex chromosome aneuploidy sca. The majority of klinefelter syndrome patients have the xxy karyotype. The presence of an extra x chromosome primarily affects the testes. A 47,xxy female with unusual genitalia springerlink. Sex chromosome aneuploidy is a very common occurrence with incidence rates in men reported to be as high as 1. Xxy men are identical in physical appearance and mental capacity to xy men. Male sex chromosome abnormalities klinefelter syndrome males inherit one or more extra x chromosomestheir genotype is xxy or more rarely xxxy or xy xxy mosaic. Apr 09, 2009 a sevenyearold girl with a y chromosome is providing new clues about a possible master switch of maleness.
Some people with 47, xxy may have no noticeable signs or symptoms features. There are 22 pairs of autosomes nonsex chromosomes and one pair of sex chromosomes. Klinefelter syndrome is a genetic condition affecting males, and it often isnt diagnosed until adulthood. 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 about one of every 500 males has an extra x chromosome, but many dont have any symptoms. Girl with y chromosome sheds light on maleness new scientist. The condition is generally not inherited from a persons parents but rather. The reason that we cant survive without an x chromosome or at least without very severe problems is the same reason that we cant survive without any other chromosome. Xxy synonyms, xxy pronunciation, xxy translation, english dictionary definition of xxy. People with this condition are born with at least one extra x chromosome. Sometimes, symptoms are more prominent and may include weaker muscles, greater height. Description klinefelter syndrome is a condition in which one or. During adolescence, they frequently have severe facial acne.
Klinefelter syndrome extra x chromosome hormone solutions. Klinefelter syndrome, also known as xxy syndrome, is a genetic disorder that involves an additional x sex chromosome in males. Jan 14, 2009 i dont know xo, but xxx and xxy are supermales and superfemales respectively. Clinical, endocrinological, and epigenetic features of the 46,xx male. The xy sexdetermination system is the sexdetermination system found in humans, most other mammals, some insects, some snakes, some fish, and some plants tree. For example, genetic men with klinefelter syndrome possess an extra x chromosome xxy or more rarely, two or three extra xs xxxy, xxxxy. Klinefelter syndrome is a fairly common genetic condition found in males only. Approximately 15% of klinefelter patients, however, are mosaics with variable phenotypes.
Learn about symptoms, diagnosis, treatment, and more. Xxy gonadal dysgenesis an inherited condition caused by an extra completemost commonlyor partial x chromosome. Klinefelter syndrome symptoms and causes mayo clinic. Females have two x chromosomes 46,xx, and males have one x and one y chromosome 46,xy. I dont know xo, but xxx and xxy are supermales and superfemales respectively. Xyy syndrome is a genetic condition that occurs when a males genes have an extra y chromosome. It is a condition that is not lifethreatening, but can have major quality of life implications throughout all. Most males are infertile because their bodies dont make enough sperm. But what happens when a male has more than two sex chromosomes.
Charlie has xyy syndrome, which is a condition where a boy has an extra y chromosome. However, males with klinefelters syndrome have an extra x chromosome 47xxy and therefore a total of 47 chromosomes. Xxyy syndrome is a sex chromosome anomaly in which males have an extra x and y chromosome. The affected individuals are male showing the sex determination role of the ychromosomes but with much reduced fertility, and a number of female secondary sexual characteristics, such as breasts, often occur. Superfemales are broader in symptoms some dont have any effects, some are infertile, and some have major disabilities. If a man has xx chromosomes it has to be with a y chromosome xxy. Klinefelter syndrome is a chromosomal condition in boys and men that can affect physical and intellectual development. It is a part of the xy sexdetermination system and x0 sexdetermination system. The xxy chromosome arrangement is one of the most common genetic variations from the xy karyotype, occurring in about 1 in 500 live male births.
Males with this condition typically have small testes that do not produce enough testosterone, which is the hormone that directs male sexual development. The person is generally otherwise normal, including normal fertility. No, the presence of the extra y chromosome in xyy males does not in and of itself produce aggressive behavior in those affected. This page exists to inform xxy men, parents, and families of their potential capabilities and right to equality.
It is sometimes referred to as a variant of klinefelter syndrome, but differs from klinefelter syndrome in many ways and is more severe. The sex chromosomes are the x chromosome and the y chromosome. 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 about one of every 500 males has an. If there is a problem with one x chromosome, the other x is likely to override it.
Yes that is possible, the xxy combination is called klienfelders syndrome named after the scientist who first identified it. This xxy chromosome arrangement is one of the most common genetic variations from the xy karyotype, occurring in about one in 500 live male births. However, although females cannot have klinefelter syndrome, they can develop a genetic problem with their sex chromosomes known as turner syndrome. Probably because of reasons of ignorance some xxy males think their additional x is fully active and their y is almost completely inactive. Xxy trisomy definition of xxy trisomy by medical dictionary. The syndrome was first identified and described in 1942 by harry fitch klinefelter, jr.
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