Klinefelter syndrome 47,XXY Ahmed Salam Lectures Medical Student “TSU” WWW.GREATASSIMPLEMEDICINE.COM

What is Klinefelter syndrome: G.S.M MEDICAL LECTURES/ Klinefelter syndrome: AHMED SALAM MD STUDENT What is Klinefelter syndrome: Klinefelter syndrome is a chromosomal condition that affects male physical and cognitive development. Its signs and symptoms vary among affected individuals. Affected individuals typically have small testes that do not produce as much testosterone as usual. Testosterone is the hormone that directs male sexual development before birth and during puberty. A shortage of testosterone can lead to delayed or incomplete puberty, breast enlargement (gynecomastia), reduced facial and body hair, and an inability to have biological children (infertility). Some affected individuals also have genital differences including undescended testes (cryptorchidism), the opening of the urethra on the underside of the penis (hypospadias), or an unusually small penis (micropenis). Older children and adults with Klinefelter syndrome tend to be taller than their peers. Compared with unaffected men, adults with Klinefelter syndrome have an increased risk of developing breast cancer and a chronic inflammatory disease called systemic lupus erythematosus. Their chance of developing these disorders is similar to that of women in the general population. Children with Klinefelter syndrome may have learning disabilities and delayed speech and language development. They tend to be quiet, sensitive, and unassertive, but personality characteristics vary among affected individuals. WWW.GREATASSIMPLEMEDICINE.COM

Causes: G.S.M MEDICAL LECTURES/ Klinefelter syndrome: AHMED SALAM MD STUDENT Causes: Most people have 46 chromosomes. Chromosomes contain all of your genes and DNA, the building blocks of the body. Two sex chromosomes determine if you become a boy or a girl. Girls normally have two XX chromosomes. Boys normally have an X and a Y chromosome. Klinefelter syndrome is when a boy is born with at least one extra X chromosome. Usually, this occurs due to one extra X. This would be written as XXY. Klinefelter syndrome occurs in about 1 out of 500 - 1,000 baby boys. Women who get pregnant after age 35 are slightly more likely to have a boy with this syndrome than younger women. WWW.GREATASSIMPLEMEDICINE.COM

Symptoms G.S.M MEDICAL LECTURES/ Klinefelter syndrome: AHMED SALAM MD STUDENT Symptoms Abnormal body proportions (long legs, short trunk, shoulder equal to hip size) Abnormally large breasts (gynecomastia) Infertility Sexual problems Less than normal amount of pubic, armpit, and facial hair Small, firm testicles Tall height WWW.GREATASSIMPLEMEDICINE.COM

Can Klinefelter syndrome be inherited? G.S.M MEDICAL LECTURES/ Klinefelter syndrome: AHMED SALAM MD STUDENT Can Klinefelter syndrome be inherited? Klinefelter syndrome and its variants are not inherited; these chromosomal changes usually occur as random events during the formation of reproductive cells (eggs and sperm) in a parent. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain one or more extra copies of the X chromosome as a result of nondisjunction. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have one or more extra X chromosomes in each of the body's cells. Mosaic 46,XY/47,XXY is also not inherited. It occurs as a random event during cell division early in fetal development. As a result, some of the body's cells have one X chromosome and one Y chromosome (46,XY), and other cells have an extra copy of the X chromosome (47,XXY). WWW.GREATASSIMPLEMEDICINE.COM

comperation G.S.M MEDICAL LECTURES/ Klinefelter syndrome: AHMED SALAM MD STUDENT WWW.GREATASSIMPLEMEDICINE.COM

Diagnosis: G.S.M MEDICAL LECTURES/ Klinefelter syndrome: AHMED SALAM MD STUDENT Diagnosis: About 10% of Klinefelter cases are found by prenatal diagnosis.[29] The first clinical features may appear in early childhood or, more frequently, during puberty, such as lack of secondary sexual characters and aspermatogenesis,[30] while tall stature as asymptom can be hard to diagnose during puberty. Despite the presence of small testes, only a quarter of the affected males are recognized as having Klinefelter syndrome at puberty[31][32] and 25% received their diagnosis in late adulthood: about 64% affected individuals are not recognized as such.[33] Often the diagnosis is made accidentally as a result of examinations and medical visits for reasons not linked to the condition.[34] The standard diagnostic method is the analysis of the chromosomes' karyotype on lymphocytes. In the past, the observation of the Barr body was common practice as well.[32] To confirm mosaicism, it is also possible to analyze the karyotype usingdermal fibroblasts or testicular tissue.[35] Other methods may be: research of high serum levels of gonadotropins (follicle- stimulating hormone and luteinizing hormone), presence of azoospermia, determination of the sex chromatin,[36] and prenatally via chorionic villus sampling oramniocentesis. 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. WWW.GREATASSIMPLEMEDICINE.COM

Treatment: G.S.M MEDICAL LECTURES/ Klinefelter syndrome: AHMED SALAM MD STUDENT Treatment: Testosterone therapy may be prescribed. This can help: Grow body hair Improve appearance of muscles Improve concentration Improve mood and self esteem Increase energy and sex drive Increase strength Most men with this syndrome are not able to get a woman pregnant. However, an infertility specialist may be able to help. A special doctor called an endocrinologist may also be helpful. WWW.GREATASSIMPLEMEDICINE.COM