Stretch marks might have a genetic basis, new research suggests.
The research, published as a letter to the editor in the Journal of Investigative Dermatology, shows that there are four genetic markers that seem to be linked with stretch marks. The study was conducted by scientists from the personal genetics company 23andMe.
The study involved genome-wide association analysis of 33,930 customers of 23andMe. All the study participants were of European descent; 13,930 people had stretch marks, while 20,862 did not.
Researchers further looked at gene variants in 4,967 women who reported the severity of their stretch marks experienced during pregnancy.
Through this analysis, researchers were able to identify four genetic regions tied to stretch marks. Specifically, they found that one particular DNA sequence variation linked with the pregnancy-related stretch marks was located closely to the elastin gene; elastin is "the major component of elastic fibers, which provide reversible extensibility to connective tissue," the researchers wrote in the study.
Stretch marks are extremely common, with anywhere from 50 to 80 percent of all people experiencing them, researchers noted. Also called "striae," they often appear as colored streaks in the skin, most commonly around the thighs, butt, arms and abdomen, the Mayo Clinic reported. Pregnant women may also have an increased risk of stretch marks due to their growing bellies. Weight gain, certain conditions and use of some medications (like corticosteroid creams) are known causes of stretch marks.