Here, we try not to talk about whatever stretch marks we may have, whether they appeared due to growth spurts, weight fluctuations, or pregnancy. They can just disappear, thank you very much.
23andMe researchers, though, took a closer look. From among their subscribers, they identified some 13,000 cases and 21,000 controls with and without stretch markers to determine whether there is a genetic influence on who develops them and who does not. They also examined a cohort of nearly 5,000 women who developed stretch marks during pregnancy.
From their genome-wide association study, which they report on in the Journal of Investigative Dermatology, Joyce Tung and her colleagues uncovered four regions that are associated with stretch marks. Intriguingly, the most strongly associated one is located very close to the elastin gene.
"Given that loose skin is a symptom of syndromes caused by deletion or loss-of-function mutations in ELN, our results support the hypothesis that variations in the elastic fiber component of the skin extracellular matrix contribute to the development of stretch marks," the researchers write.
A separate region, near the SRPX, was more common in their cohort of pregnant women. The possible role of that gene, 23andMe's blog adds, remains to be investigate.
Tung and her colleagues add that their findings may help uncover therapies that are more effective than the current common practices of applying salves such as cocoa butter and vitamin E, or laser treatments.
We, however, are trying ignoring any stretch marks to see if they go away.