From the Research
Yes, cells can lose an X chromosome due to aging, with the frequency of X chromosome loss increasing significantly with age, as demonstrated by a study published in 2007 1. This phenomenon, known as X chromosome loss, occurs more frequently as people get older, particularly in women. The process happens when cells divide and chromosomes are not properly distributed to daughter cells, resulting in some cells having only one X chromosome instead of two (in females) or none (in males). Some key points to consider include:
- The frequency of X chromosome loss ranges from 0.07% at age <16 years to 7.3% at >65 years of age, showing a highly significant quadratic relationship between X chromosome loss and ageing 1.
- This loss is most commonly observed in blood cells and has been linked to various age-related conditions including cancer, autoimmune disorders, and cardiovascular disease.
- The mechanism behind age-related X chromosome loss involves deterioration of chromosome maintenance systems, telomere shortening, and declining efficiency of cell division checkpoints, as suggested by research on DNA damage and aging 2.
- Research suggests that by age 65, approximately 1-2% of female blood cells may have lost an X chromosome, with this percentage increasing with advancing age, contributing to the genomic instability that characterizes cellular aging and may play a role in the development of age-related diseases. Some other studies have investigated the relationship between aging and DNA repair, including a study published in 2007 that discussed changes in DNA repair during aging 3, and a study published in 2010 that explored epigenetic alterations in aging 4. However, the most relevant and recent study on X chromosome loss and aging is the one published in 2007 1, which provides a graphic representation of the minimum baseline age-related rate of X chromosome loss. Another study published in 1994 investigated the correlation between senescence and DNA repair in cells from young and old individuals and in premature aging syndromes, and found a striking parallelism between reduced maximal lifespan, elevated levels of spontaneous chromosomal breaks, and diminished reactivation of in vitro injured plasmid after transfection in cells from old individuals and from patients with premature senescence syndromes 5. Additionally, a study published in 2021 discussed the central role of DNA damage in the ageing process, suggesting that DNA damage affects most, if not all, aspects of the ageing phenotype, making it a potentially unifying cause of ageing 2. Overall, the evidence suggests that X chromosome loss is a common occurrence in aging cells, particularly in women, and may contribute to the development of age-related diseases.