|Embryology - 22 Mar 2019 Expand to Translate|
|Google Translate - select your language from the list shown below (this will open a new external page)|
العربية | català | 中文 | 中國傳統的 | français | Deutsche | עִברִית | हिंदी | bahasa Indonesia | italiano | 日本語 | 한국어 | မြန်မာ | Pilipino | Polskie | português | ਪੰਜਾਬੀ ਦੇ | Română | русский | Español | Swahili | Svensk | ไทย | Türkçe | اردو | ייִדיש | Tiếng Việt These external translations are automated and may not be accurate. (More? About Translations)
|Educational Use Only - Embryology is an educational resource for learning concepts in embryological development, no clinical information is provided and content should not be used for any other purpose.|
Klinefelter syndrome (47,XXY, XXY syndrome or condition, XXY trisomy) affects male physical and cognitive development. The extra copy of genes on the X chromosome interferes with male sexual development and can prevent the normal function of the testis testes, reducing the levels of testosterone. The signs and symptoms vary among affected individuals.
Rare variations include 47,XXY/46,XY (mosaic syndrome) and Poly-X Klinefelter syndrome: 48,XXYY (or tetrasomy), 48,XXXY (or tetrasomy) and 49,XXXXY (or pentasomy).
First described in 1942 by Dr Harry Klinefelter.
Some Recent Findings
|More recent papers|
This table allows an automated computer search of the external PubMed database using the listed "Search term" text link.
<pubmed limit=5>Klinefelter syndrome</pubmed>
Affects male physical and cognitive development. Small testes that do not produce as much testosterone as usual.
- 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 - undescended testes (cryptorchidism), (hypospadias), or an unusually small penis (micropenis).
- Children may have learning disabilities and delayed speech and language development. Tend to be quiet, sensitive, and unassertive, but personality characteristics vary among affected individuals.
- Older children and adults tend to be taller than their peers.
(Text modified from Genetics Home Reference - Klinefelter syndrome)
Molecular Genetics Tests
- Detection of homozygosity
- Deletion/duplication analysis
- Targeted variant analysis
- Sequence analysis of the entire coding region
- Klinefelter HF. Reifenstein EC. and Albright F. Syndrome characterized by gynecomastia aspermatogenes without A-Leydigism and increased excretion of follicle stimulating hormone. (1942) J Clin Endocrinol Metab. 2:615–627.
Search Pubmed: Klinefelter syndrome
External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.
- Genetics Home Reference Klinefelter syndrome
- Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link
Cite this page: Hill, M.A. (2019, March 22) Embryology Klinefelter syndrome. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Klinefelter_syndrome
- © Dr Mark Hill 2019, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G