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Review
. 2023 Apr 26;12(5):e230024.
doi: 10.1530/EC-23-0024. Print 2023 May 1.

Morbidity, mortality, and socioeconomics in Klinefelter syndrome and 47,XYY syndrome: a comparative review

Lukas Ochsner Ridder  1   2 , Agnethe Berglund  2   3 , Kirstine Stochholm  1 , Simon Chang  1   4 , Claus H Gravholt  1   2   4
Affiliations
Review

Morbidity, mortality, and socioeconomics in Klinefelter syndrome and 47,XYY syndrome: a comparative review

Lukas Ochsner Ridder et al. Endocr Connect. .

Abstract

Context: Klinefelter syndrome (KS, 47,XXY) and 47,XYY syndrome are genetic conditions characterized by a supernumerary sex chromosome. The conditions share many traits, but considerable phenotypic differences are seen between the two. Focusing on morbidity, mortality, and socioeconomics, this review highlights similarities and differences.

Methods: Relevant literature was identified through PubMed with the following search terms; 'Klinefelter', '47,XXY', '47,XYY', and 'Jacobs syndrome'. Included journal articles were chosen at the authors' discretion.

Results: KS and 47,XYY are the most common sex chromosome disorders in males, with an expected prevalence of 152 and 98 per 100,000 newborn males, respectively. Non-diagnosis is extensive, as only about 38% of KS and 18% of 47,XYY are diagnosed. Both conditions are associated with an increased mortality risk and increased risk of a variety of diseases and other health-related problems affecting virtually every organ system. Early diagnosis seems to predict a lesser comorbidity burden. Neurocognitive deficits as well as social and behavioral problems are commonly described. Both syndromes are associated with poor socioeconomicfor example, lower income and educational level and higher rates of crime. Infertility is a hallmark of KS, but fertility seems also reduced in 47,XYY.

Conclusion: Being born as a boy with an extra X or Y chromosome is associated with increased mortality and excess morbidity, partially expressed in a sex chromosome-specific pattern.Both syndromes continue to be greatly underdiagnosed, even thoughearly intervention may improve the overall outcome. Earlier diagnosis to initiate timely counseling and treatment should be emphasized.

Keywords: 47,XYY; Jacobs syndrome; Klinefelter syndrome; morbidity; mortality.

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Conflict of interest statement

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Figures

Figure 1
Figure 1
Abnormalities and diseases in KS males. *Testosterone may possibly positively impact several features of KS (12).
Figure 2
Figure 2
Abnormalities and diseases present in 47,XYY males (32, 36, 90, 91).
See this image and copyright information in PMC

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