klinefelter syndrome

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  • 1. Klinefeltersyndrome(47,XXY)By Egorov Peter

2. Klinefelter syndrome IndividualswithKlinefeltersyndromehave at leasttwo Xchromosomes and at leastone Ychromosome.(XXY) 3. 47, XXY and XXY syndrome(XXY)Because of the extra chromosome, individuals withthe condition are usually referred to as :47,XXYXXYMales=This chromosome constitution (karyotype)exists in roughly between 1:500 to 1:1000 livemale births 4. CauseThe extra X chromosome is retained because ofa nondisjunction event during:(XXY) Meiosis I (gametogenesis) Meiosis II in females 5. Meiosis I (gametogenesis) Nondisjunction occurs when homologouschromosomes (X and Y sex chromosomes) fail toseparate, producing a sperm with an X and a Ychromosome. Fertilizing a normal (X) egg produces an XXYoffspring. The XXY chromosome arrangement is one of the mostcommon genetic variations from the XY karyotype,occurring in about 1 in 500 live male births.(XXY) 6. Meiosis I (gametogenesis)(XXY)!!! 7. Meiosis II in females Another mechanism for retaining the extra Xchromosome is through a nondisjunction event duringmeiosis II in the female. Nondisjunction will occur when sister chromatids on thesex chromosome, in this case an X and an X, fail toseparate. An XX egg is produced which, when fertilized with a Ysperm, yields XXY offspring.(XXY) 8. Meiosis II in females(XXY)!!! 9. Signs and symptomsSigns and symptoms of Klinefelter syndromevary by age(XXY) 10. Babies: Weak muscles Slow motor development taking longer than averageto sit up, crawl and walk Delay in speaking Quiet, docile personality Problems at birth, such as testicles that havent descendedinto the scrotum(XXY)Signs and symptoms 11. Boys and teenagers: Taller than average stature Longer legs, shorter torsoand broader hips comparedwith other boys Absent, delayed orincomplete puberty After puberty, less muscularbodies and less facial andbody hair compared withother teens Small, firm testicles Small penis(XXY) Enlarged breast tissue(gynecomastia) Weak bones Low energy levels Shyness Difficulty expressingfeelings or socializing Problems with reading,writing, spelling or math Attention problemsSigns and symptoms 12. Men: Weak bones Decreased facial andbody hair Enlarged breast tissue Decreased sex drive orsexual problemsSigns and symptoms Infertility Small testicles and penis Taller than average stature 13. (XXY) 14. Variations 48,XXYY 48,XXXY The incidence of 49,XXXXY is 1 in 85,0000to 100,000 male births(XXY)occur in 1 in 18,00050,000male births. 15. Mosaic or mosaicismMosaic or mosaicism donates the presence of two or morepopulations of cells with different genotypes in oneindividual who has developed from a single fertilized egg Males with Klinefelter syndrome may have a mosaic47,XXY/46,XY constitutional karyotype and varyingdegrees of spermatogenic failure. Mosaicism 47,XXY/46,XX with clinical featuressuggestive of Klinefelter syndrome is very rare. Thus far,only about 10 cases have been described in literature.(XXY) 16. It is interesting Analogous XXY syndromes are known to occur in cats -specifically, the presence of calico(a spotted or parti-coloredcoat that is predominantly white, with patches of two othercolors (often the two other colors are orange tabby andblack )) or tortoiseshell markings in male cats is an indicatorof the relevant abnormal karyotype. As such, male cats with calico or tortoiseshell markings are amodel organism for Klinefelter syndrome.(XXY) 17. (XXY)Percentages of Klinefelters diagnosis divided by agegroups, with most diagnoses occurring in adulthood 18. Diagnosing Klinefelter SyndromeThe greatest chances to make Klinefeltersdiagnosing are in following times of life:Before or shortly after birthEarly childhoodAdolescenceAdulthood.For males in which Klinefelter syndrome is suspected, aspecial blood test is recommended to confirm theKlinefelter syndrome diagnosis.(XXY) 19. Tests Blood test: Blood test called a karyotype and is the standard diagnostic method Test looks at a persons chromosomes Prenatal Testing: many males have been diagnosed through amniocentesis orchorionic villus sampling (CVS) In amniocentesis, a sample of the fluid surrounding the fetus iswithdrawn CVS is similar to amniocentesis. The procedure is done in thefirst trimester (during the fist three month of pregnancy, itsimportant to establish a foundation of good health) and the fetalcells needed for examination are taken from the placenta(XXY) 20. Amniocentesis procedure 21. Chorionic villus sampling (CVS) 22. About 10% of Klinefelter cases are found by prenataldiagnosis. Only a quarter of the affected males are recognized ashaving Klinefelter syndrome at puberty (despite thepresence of small testes ) 25% received their diagnosis in late adulthood (about64% affected individuals are not recognized as such) Often the diagnosis is made accidentally as a result ofexaminations and medical visits for reasons not linked tothe condition(XXY)Some facts 23. Treatment Testosterone treatment should begin at puberty: can normalize body proportions and promote development ofnormal secondary sex characteristics but does not treat infertility, gynecomastia and small testes By 2010 over 100 successful pregnancies have been reportedusing IVF (In vitro fertilization) technology with surgicallyremoved sperm material from men with Klinefelter syndrome The results of a study on 87 Australian adults with the syndromeshows: Who have had a diagnosis and appropriate treatment from a veryyoung age had a significant benefit with respect to those whohad been diagnosed in adulthood(XXY) 24. IVF (In vitro fertilization) Is a process by which an egg is fertilized by sperm outside the body: invitro Involves: monitoring a womans ovulatory process removing ovum or ova (egg or eggs) from the womans ovaries letting sperm fertilize them in a fluid medium in a laboratory. When a womans natural cycle is monitored to collect a naturallyselected ovum (egg) for fertilization (it is known as natural cycle IVF)(XXY) A "naked" eggthe fertilized egg (zygote) is then transferredto the patients uterus with the intention ofestablishing a successful pregnancy 25. GynecomastiaPhoto of male with severe asymmetrical gynecomastia, followed bya photo of the same male after a liposuction procedure. 26. Gross Pathology:A large glandular mass of male breast tissue, surgically removed 27. Epidemiology This syndrome, evenly spread in all ethnic groups, has a prevalence of1-2 subjects every 1000 males in the general population 3.1 % of infertile males have Klinefelter syndrome The prevalence of the syndrome has increased over the past decades(according to a meta-analysis) However, this does not appear to be correlated with the increase of theage of the mother at conception The results of a study on 87 Australian adults with the syndromeshows: Who have had a diagnosis and appropriate treatment from a veryyoung age had a significant benefit with respect to those whohad been diagnosed in adulthood(XXY) 28. History of Klinefelter Syndrome It was first indentified in 1942. By the late1950s, the cause of Klinefelter syndromewas discovered. In 1942, Dr. Harry Klinefelter and hiscoworkers at the Massachusetts GeneralHospital in Boston published a report about9 men who had enlarged breasts, sparsefacial and body hair, small testes, and aninability to produce sperm. By the late 1950s, researchers discoveredthat men with Klinefelter syndrome.(XXY) 29. In the early 1970s Researchers around the world sought to identify males having theextra chromosome by screening large numbers of newbornbabies. One of the largest of these studies checked the chromosomes ofmore than 40,000 infants. The XXY chromosome arrangement appears to be one of themost common genetic abnormalities known (1 in 500 to 1 in1,000 male births) Not a lot actually have Klinefelter syndrome symptoms. Manymen live out their lives without ever suspecting that they have anadditional chromosome.(XXY) 30. Sources: http://www.hindawi.com/journals/ije/2012/324835/ http://en.wikipedia.org/wiki/Klinefelter_syndrome http://genetics.emedtv.com/klinefelter-syndrome/diagnosing-klinefelter-syndrome.html http://jama.jamanetwork.com/article.aspx?articleid=183701 http://www.ncbi.nlm.nih.gov/ http://www.researchgate.net/publication/20250975_Klinefelters_syndrome_with_hypospadias_and_bilateral_cryptorchidism http://emedicine.medscape.com/article/945649-overview#showall http://www.patient.co.uk/health/klinefelters-syndrome http://www.yourhormones.info/endocrine_conditions/klinefelters_syndrome.aspx http://howshealth.com/klinefelter-syndrome/ http://medical-dictionary.thefreedictionary.com/Klinefelter+syndrome


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