Klinefelter syndrome (KS) also known as 47,XXY or XXY, is the set of symptoms that result from two or more X chromosomesin males. The primary feature is sterility. Often symptoms may be subtle and many people do not realize they are affected. Sometimes symptoms are more prominent and may include weaker muscles, greater height, poor coordination, less body hair, smaller genitals, breast growth, and less interest in sex. Often it is only at puberty that these symptoms are noticed. Intelligence is usually normal; however, reading difficulties and problems with speech are more common. Symptoms are typically more severe if three or more X chromosomes are present.
Klinefelter syndrome usually occurs randomly. An older mother might increase the risk slightly. The condition is not inherited from one's parents. The underlying mechanisms involves at least one extra X chromosome in addition to a Y chromosome such that there is a total of 47 or more chromosomes rather than usual 46. KS is diagnosed by the genetic test known as a karyotype.
While there is no cure, a number of treatments may help. Physical therapy, speech and language therapy, counselling, and adjustments of teaching methods may be useful. Testosterone replacement may be used in those who have significantly low levels. Enlarged breasts may be removed by surgery. About half of males affected with the help of assisted reproductive technology have a chance of having children; however, this is expensive and carries risks. Males appear to have a higher risk of breast cancer than typical but still lower than that of females. The condition has a nearly normal life expectancy.
Klinefelter syndrome is one of the most common chromosomal disorders, occurring in 1:500 to 1:1000 live male births. It is named after Harry Klinefelter who identified the condition in the 1940s. 1956 saw the identification of the extra X chromosome. Mice can also have the XXY syndrome, making them a useful research model.
We researched this topic for you and found the following best online resources. They are categorized into basic, advanced, and research level based on the extent of information you need. You will be taken to the respective websites by pressing on the links below.
Basic information:
http://www.webmd.com/men/tc/klinefelter-syndrome-topic-overview web md klinefelter syndrome - topic overview
http://www.nhs.uk/conditions/klinefelters-syndrome/pages/introduction.aspx nhs uk klinefelter syndrome
http://www.mayoclinic.org/diseases-conditions/klinefelter-syndrome/basics/definition/con-20033637 mayo clinic klinefelter syndrome
https://www.genome.gov/19519068/learning-about-klinefelter-syndrome/ national human genomic research institute klinefelter syndrome
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/klinefelter-syndrome better health klinefelter syndrome
http://kidshealth.org/en/teens/klinefelter.html kids health klinefelter syndrome
https://medlineplus.gov/klinefelterssyndrome.html medline plus klinefelter syndrome
https://medlineplus.gov/ency/article/000382.htm medline plus klinefelter syndrome
http://www.merckmanuals.com/home/children-s-health-issues/chromosomal-and-genetic-abnormalities/klinefelter-syndrome merck manuals klinefelter syndrome
http://www.nytimes.com/health/guides/disease/klinefelter-syndrome/overview.html new york times klinefelter syndrome
http://umm.edu/health/medical/ency/articles/klinefelter-syndrome university of maryland medical center klinefelter syndrome
http://www.healthdirect.gov.au/klinefelter-syndrome health direct klinefelter syndrome
http://www.everydayhealth.com/klinefelter-syndrome/guide/ every day health klinefelter syndrome
http://www.healthlinkbc.ca/healthtopics/content.asp?hwid=hw183686 health link bc klinefelter syndrome
https://www.healthychildren.org/english/ages-stages/gradeschool/puberty/pages/klinefelter-syndrome.aspx healthy children klinefelter syndrome
https://myhealth.alberta.ca/health/pages/conditions.aspx?hwid=hw183686& my health alberta ca klinefelter syndrome
Advanced information:
https://ghr.nlm.nih.gov/condition/klinefelter-syndrome genomic home reference klinefelter syndrome
http://emedicine.medscape.com/article/945649-overview medscape klinefelter syndrome
http://www.medicinenet.com/klinefelter_syndrome/article.htm medicine net klinefelter syndrome
http://patient.info/in/health/klinefelters-syndrome-leaflet patient klinefelter's syndrome
http://rarediseases.org/rare-diseases/klinefelter-syndrome/ national oranisation for rare diseases klinefelter syndrome
http://www.aafp.org/afp/2005/1201/p2259.html klinefelter syndrome by daniel j. wattendorf, maj, mc, usaf, and maximilian muenke, m.d., national human genome research institute, national institutes of health, bethesda, maryland am fam physician. 2005 dec 1;72(11):2259-2262.
https://www.britannica.com/science/klinefelter-syndrome britannica klinefelter syndrome
http://radiopaedia.org/articles/klinefelter-syndrome radiopedia klinefelter syndrome
http://www.medindia.net/patients/patientinfo/klinefelterssyndrome.htm medindia klinefelter syndrome
http://www.rightdiagnosis.com/k/klinefelter_syndrome/intro.htm right diagnosis klinefelter syndrome
Research:
chopra r, chander a, jacob jj. the eye as a window to rare endocrine disorders. indian j endocr metab [serial online] 2012 [cited 2016 aug 22];16:331-8. available from: http://www.ijem.in/text.asp?2012/16/3/331/95659
høst c, skakkeb'k a, groth ka, bojesen a. the role of hypogonadism in klinefelter syndrome. asian j androl [serial online] 2014 [cited 2016 aug 22];16:185-91. available from: http://www.ajandrology.com/text.asp?2014/16/2/185/122201 - doi: 10.4103/1008-682x.122201
http://ojrd.biomedcentral.com/articles/10.1186/1750-1172-1-42 klinefelter syndrome and other sex chromosomal aneuploidies by jeannie visootsak et al., orphanet journal of rare diseases20061:42 doi: 10.1186/1750-1172-1-42
http://www.hindawi.com/journals/ije/2012/324835/ néstor pacenza, titania pasqualini, silvia gottlieb, et al., “clinical presentation of klinefelter's syndrome: differences according to age,” international journal of endocrinology, vol. 2012, article id 324835, 6 pages, 2012. doi:10.1155/2012/324835
accardo g, vallone g, esposito d, barbato f, renzullo a, conzo g, docimo g, esposito k, pasquali d. testicular parenchymal abnormalities in klinefelter syndrome: a question of cancer? examination of 40 consecutive patients. asian j androl [serial online] 2015 [cited 2016 aug 22];17:154-8. available from: http://www.ajandrology.com/text.asp?2015/17/1/154/128514 - doi: 10.4103/1008-682x.128514
http://www.scielo.br/scielo.php?script=sci_arttext&pid=s0004-282x2006000200024 arq. neuro-psiquiatr. vol.64 no.2a são paulo june 2006 http://dx.doi.org/10.1590/s0004-282x2006000200024 atypical presentation of prader-willi syndrome with klinefelter (xxy karytype) and craniosynostosis by daniel r. carvalho et al.,
http://www.hindawi.com/journals/ije/2016/3032759/ stefano stagi, mariarosaria di tommaso, cristina manoni, et al., “bone mineral status in children and adolescents with klinefelter syndrome,” international journal of endocrinology, vol. 2016, article id 3032759, 9 pages, 2016. doi:10.1155/2016/3032759
mehta a, mielnik a, schlegel pn, paduch da. novel methylation specific real-time pcr test for the diagnosis of klinefelter syndrome. asian j androl [serial online] 2014 [cited 2016 aug 22];16:684-8. available from: http://www.ajandrology.com/text.asp?2014/16/5/684/125914 - doi: 10.4103/1008-682x.125914
http://www.hindawi.com/journals/criog/2015/980749/ esther perez-carbajo, ignacio zapardiel, luis sanfrutos-llorente, sara cruz-melguizo, cristina martinez-payo, and enrique iglesias-goy, “prenatal diagnosis of concurrent achondroplasia and klinefelter syndrome,” case reports in obstetrics and gynecology, vol. 2015, article id 980749, 2 pages, 2015. doi:10.1155/2015/980749
jayaraman ar, poguri m, siva n. a case report of klinefelter syndrome with schizophrenia-like psychosis and seizure disorder. indian j psychol med [serial online] 2015 [cited 2016 aug 22];37:364-5. available from: http://www.ijpm.info/text.asp?2015/37/3/364/162922
chennuri v, kashyap r, tamhankar p, phadke s. chronic myeloid leukemia in case of klinefelter syndrome. indian j hum genet [serial online] 2014 [cited 2016 aug 22];20:69-71. available from: http://www.ijhg.com/text.asp?2014/20/1/69/132760
http://www.scopemed.org/fulltextpdf.php?mno=208874 klinefelter’s syndrome in azoospermic infertile males of vidarbha region, central india by maske gl et al. int j res med sci. 2016 apr;4(4):1045-1050 doi: http://dx.doi.org/10.18203/2320-6012.ijrms20160781
muhammed k, sofia b. indolent ulcers of leg and foot in klinefelter's syndrome associated with straight back syndrome. indian j dermatol venereol leprol [serial online] 2002 [cited 2016 aug 22];68:109-11. available from: http://www.ijdvl.com/text.asp?2002/68/2/109/12619
Other helpful resources(support groups):
http://www.ksa-uk.net/ klinefelter syndrome association
http://www.aaksis.org/ the american association for klinefelter syndrome
http://www.isna.org/faq/conditions/klinefelter intersex society of north america
http://www.klinefelter.org.uk/ klinefelter organisation
Related videos:
https://www.youtube.com/watch?v=ijhb0_gqzts klinefelter's syndrome
https://www.youtube.com/watch?v=c9ne4cwy9t4 what is klinefelter's syndrome
https://www.youtube.com/watch?v=b3mgcuh7pr4 klinefelter's syndrome
https://www.youtube.com/watch?v=6qtpdsjc9cs klinefelter's syndrome
https://www.youtube.com/watch?v=7ddzb4yq5xe klinefelter's syndrome - crash! medical review series
https://www.youtube.com/watch?v=_sycseon80a klinefelter's syndrome
Presentations/quiz/newspaper articles:
http://theconversation.com/klinefelters-syndrome-being-unable-to-produce-testosterone-has-serious-implications-for-men-57488 the conversation klinefelter’s syndrome: being unable to produce testosterone has serious implications for men
http://www.dailymail.co.uk/health/article-1346474/klinefelters-syndrome-adele-markham-fought-20-years-woman.html daily mail the little boy with rare genetic disorder who fought for 20 years to be a woman
read more: http://www.dailymail.co.uk/health/article-1346474/klinefelters-syndrome-adele-markham-fought-20-years-woman.html#ixzz4i78fab4j
http://www.genengnews.com/gen-news-highlights/researchers-work-with-novel-tool-to-detect-klinefelter-syndrome/81251663/ gen news researchers work with novel tool to detect klinefelter syndrome