Mosaic loss of chromosome Y

Mosaic loss of chromosome Y
The Y chromosome.
Specialty	Medical genetics

Mosaic loss of chromosome Y (mLOY) also known as loss of chromosome Y (LOY) occurs to many men in some cells due to aging. Instead of the expected 46,XY karyotype, the affected cells have a 45,X karyotype due to the loss of the Y chromosome.[1]

Discovery

The occurrence of LOY was discovered in 1963.[2]

Risk factors

"Age, genetic variants, ChrY structural aberrations and environmental stressors" such as smoking tobacco are all risk factors for developing LOY.[1][3] The prevalence increases exponentially with age[3] and more than 40 percent of men over 70 are affected.[1] Unlike loss of autosomal chromosomes, loss of sex chromosomes except the one active X chromosome does not typically cause cell death. Elderly women also experience mosaic loss of chromsome X, but it is less common than LOY.[1]

Health implications

LOY in a small proportion of leukocytes (white blood cells) has been associated with a number of diseases such as cancer, Alzheimer's disease, and cardiovascular disease. Why this is the case is not understood.[4] LOY can also occur in cells of the buccal mucosa and dorsolateral prefrontal cortex.[3]

References

1. Fukami, Maki; Miyado, Mami (January 2022). "Mosaic loss of the Y chromosome and men's health". Reproductive Medicine and Biology. 21 (1): e12445. doi:10.1002/rmb2.12445. PMC 8967293. PMID 35386373.
2. Walsh, Kenneth (14 July 2022). "Y chromosome loss through aging can lead to an increased risk of heart failure and death from cardiovascular disease, new research finds". The Conversation. Retrieved 16 November 2023.
3. Guo, Xihan; Dai, Xueqin; Zhou, Tao; Wang, Han; Ni, Juan; Xue, Jinglun; Wang, Xu (2020). "Mosaic loss of human Y chromosome: what, how and why". Human Genetics. 139 (4): 421–446. doi:10.1007/s00439-020-02114-w. PMID 32020362. S2CID 211036885.
4. Lau, Yun-Fai Chris (13 August 2020). "Y chromosome in health and diseases". Cell & Bioscience. 10 (1): 97. doi:10.1186/s13578-020-00452-w. ISSN 2045-3701. PMC 7427063. PMID 32817785.