Peter Gillespie ’25
Why do some people experience one broken bone after another, while others could go their whole lives without a single fracture? Is the likelihood of an osteopathic injury just a coincidence, or is one’s genetic makeup rolling the dice for them? To answer this question, Hyo Geun Choi and his colleagues at Hallym University compared the histories of osteopathic injuries and bone densities of identical twins to fraternal twins. While fraternal twins are no more identical than regular siblings, identical twins have nearly identical genetic makeups. Previous studies have even shown that similar stress fractures can occur in the same bones of identical twins. Due to similarities in genetic makeup between identical twins, investigations of identical twins could provide insight on the influence of genetics in predicting osteopathic injuries.
To explore the impact of genetics on injury risk, the team conducted interviews with 516 pairs of identical twins and 121 pairs of fraternal twins to determine their histories of fractures, osteoporosis, osteoarthritis (OA), and rheumatoid arthritis (RA). These questionnaires were coupled with DEXA T-scans, a body composition analysis that measures bone mineral density. This comparative analysis found that identical twins had significantly more similarities in their bone scans than did fraternal twins, suggesting that genetics indeed play a role in the development of bone. However, despite similar bone densities between identical twins, they were no more likely to have similar histories of bone fractures, osteoporosis, OA, or RA than were fraternal twins.
These findings suggest that genes do play a role in the development of bone – as revealed by the similar bone mineral densities– but they may not be predictive of osteopathic injury. The investigators suggest that other factors, such as changes to gene expression throughout one’s lifetime as well as differences in lifestyle and environment, could be the reasons for this discordance. As such, when two people collide, it is not necessarily the genes that decide the risk of injury, but rather the differences in gene expression, lifestyle, or, perhaps, mere coincidence.
 H. Choi, et al., Comparison of the coincidence of osteoporosis, fracture, arthritis histories, and DEXA T-score between monozygotic and dizygotic twins: a cross-sectional study using KoGES HTS data. Nutrients 14, 1-11 (2022). doi: 10.3390/nu14183836.
 Image retrieved from: https://www.pexels.com/photo/young-sad-woman-with-broken-leg-on-sofa-4497828/