KLINEFELTER SYNDROME

Yağız Fırat BORAN11-D104

ABOUT KLINEFELTER• The syndrome was named after Harry Klinefelter.

• This syndrome spread in all ethnic groups.

• 3.1% of infertile(kısır) males have Klinefelter syndrome.

• A 2002 literature review of elective abortion rates found that approximately 58% of pregnancies in the United States with a diagnosis of Klinefelter syndrome were terminated.

ABOUT KLINEFELTER• 1-2 subjects every 1000 males in the general population.

• According to a meta-analysis, the prevalence of the syndrome has increased over the past decades.

• There is reaseach suggesting klinefelter syndrome substantially decreases life expectancy among affected individuals.

• Many of these people may not show symptoms.

ABOUT KLINEFELTER• Often the diagnosis is made accidentally as a result of examinations and medical visits for reasons not linked to the condition.

• Principal effects include hypogonadism and sterility(KISIRLIK).

• Other mammals also have the XXY syndrome, including mice.

• The term hypogonadism in XXY symptoms is often misinterpreted to mean "small testicles" or "small penis".

CAUSES• Klinefelter syndrome is a genetic disorder in which there is at least one extra X chromosome to a standard human male karyotype, for a total of 47 chromosomes rather than the 46 found in genetically typical humans.

• Klinefelter syndrome have at least two X chromosomes and at least one Y chromosome. Because of the extra chromosome, individuals with the condition are usually referred to as "XXY males", or "47,XXY males".

CAUSES • TYPES;  TYPE 1: producing a sperm with an X and a Y chromosome. Fertilizing a normal (X) egg produces an XXY offspring.

TYPE 2: X and an X, fail to separate. (meiosis) An XX egg is produced which, when fertilized with a Y sperm, yields XXY offspring.

TYPE 1

Sperm has one x and y chromosome

TYPE 2Female has double chromosome

INFORMATION• 48,XXYY and 48,XXXY occur in 1 in 18,000–50,000 male births. The incidence of 49,XXXXY is 1 in 85,000 to 100,000 male births. These variations are extremely rare. Additional chromosomal material can contribute to cardiac, neurological, orthopedic and other anomalies.

• There have been some reports of individuals with Klinefelter syndrome who also have other chromosome abnormalities, such as Down syndrome.

SYMPTOMS• The degree to which XXY males are affected, both physically and developmentally, differs widely from person to person.

• Males may have weaker muscles and reduced strength. As they grow older, they tend to become taller than average. They may have less muscle control and coordination than other boys their age.

SYMPTOMS• Boys do not produce as much testosterone as other boys, they have a less muscular body, less facial and body hair, and broader hips.

• As teens, XXY males may have larger breasts, weaker bones, and a lower energy level than other boys.

• XXY males are also more likely than other men to have certain health problems, which typically affect females, such as autoimmune disorders, breast cancer, venous thromboembolic disease, and osteoporosis.

SYMPTOMS•  X-linked recessive conditions occur less frequently in XXY males than in normal XY males, since these conditions are transmitted by genes on the X chromosome, and people with two X chromosomes are typically only carriers rather than affected by these X-linked recessive conditions.

• Some degree of language learning or reading impairment may be present, and neuropsychological testing often reveals deficits in executive functions, although these deficits can often be overcome through early intervention.

SYMPTOMS• Here may also be delays in motor development which can be addressed through occupational therapy and physical therapy. XXY males may sit up, crawl, and walk later than other infants; they may also struggle in school, both academically and with sports.

DIAGNOSIS• Despite the presence of small testes, only a quarter of the affected males are recognized as having Klinefelter syndrome at puberty and 25% received their diagnosis in late adulthood.

• About 64% affected individuals are not recognized as such.

DIAGNOSIS• Often the diagnosis is made accidentally as a result of examinations and medical visits for reasons not linked to the condition.

• The standard diagnostic method is the analysis of the chromosomes' karyotype on lymphocytes.

• KARYOTYPE: number and appearance of chromosomes in the nucleus of a eukaryotic cell.

• LYMPHOCYTES: (Lökosit)  white blood cell in the vertebrate immune system,

DIAGONISIS• Amniocentesis is another test for analysis.

• A prenatal test in which amniotic fluid is taken out of the uterus.

• It is a risky method. It causes abortion. But the most certain method is amniocentesis.

TREATMENTS• The only reliable method of identification is karyotype testing.

• By 2010 over 100 successful pregnancies have been reported using IVF technology with surgically removed sperm material from males with Klinefelter syndrome.

• IVF: In vitro fertilisation (Tüp bebek) a process by which an egg is fertilised by sperm outside the body.

• Hormonel injections and pills: They help to get a normal level of secondary sex characteristic. But these methods have adverse outcomes and it is not a constant solution.

EXTRAS• The genetic variation is irreversible. Often individuals that have noticeable breast tissue or hypogonadism experience depression and/or social anxiety because they are outside of social norms. 

EXTRAS• Children with XXY differ little from other children. Although they can face problems during adolescence, often emotional and behavioural, and difficulties at school, most of them can achieve full independence from their families in adulthood. Most can lead a normal, healthy life.

• It has the second place in extra chrosome diseases.

• It has the first place in sexual chromosome diseases.

RESOURCES• http://en.wikipedia.org/wiki/Klinefelter_syndrome

• http://www.itusozluk.com/goster.php/klinefelter+sendromu

• http://www.mayoclinic.org/diseases-conditions/klinefelter-syndrome/basics/definition/con-20033637