Show Summary Details
Page of

Klinefelter’s syndrome 

Klinefelter’s syndrome
Chapter:
Klinefelter’s syndrome
Author(s):

Dieter Meschede

and Eberhard Nieschlag

DOI:
10.1093/med/9780199235292.003.9076
Page of

PRINTED FROM OXFORD MEDICINE ONLINE (www.oxfordmedicine.com). © Oxford University Press, 2016. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Medicine Online for personal use (for details see Privacy Policy and Legal Notice).

date: 17 November 2019

When in 1942 Harry Klinefelter and his colleagues described the condition carrying his name (1), its aetiology was unknown. In 1959 Jacobs and Strong (2) recognized the chromosomal basis of the disorder, until then solely defined through a set of clinical criteria. Ever since, diagnosing Klinefelter’s syndrome has required the demonstration of the 47,XXY karyotype or one of its rare variants. The occasional patient with a normal karyotype who fulfils the original clinical criteria, namely small testes, azoospermia, gynaecomastia, and elevated urinary FSH, is no longer considered as having Klinefelter’s syndrome (3). Individuals with the karyotypes 48,XXYY, 48,XXXY, and 49,XXXXY are also subsumed under the Klinefelter’s syndrome category. While these patients display all the signs and symptoms typical of the 47,XXY karyotype, they are burdened by significant additional health problems, most notably mental retardation, and malformations. For this reason, these conditions should be designated as 48,XXYY, 48,XXXY, or 49,XXXXY syndromes, respectively, and should be set apart from Klinefelter’s syndrome in the narrower sense.

Access to the complete content on Oxford Medicine Online requires a subscription or purchase. Public users are able to search the site and view the abstracts for each book and chapter without a subscription.

Please subscribe or login to access full text content.

If you have purchased a print title that contains an access token, please see the token for information about how to register your code.

For questions on access or troubleshooting, please check our FAQs, and if you can't find the answer there, please contact us.