A Replication Study Confirmed the EDAR Gene to Be a Major Contributor to Population Differentiation Regarding Head Hair Thickness in Asia

In a study examining the genetic basis of hair thickness variation among Asian populations, researchers found that a single nucleotide polymorphism (SNP) in the ectodysplasin A receptor gene (EDAR 1540T/C) was significantly associated with hair fiber thickness in a Japanese population, confirming previous findings in Thai-Mai and Indonesian groups. The association was highly significant (P = 2.7 × 10−6) in the Japanese sample and even stronger (P = 3.8 × 10−10) when data from all three populations were combined, surpassing the influence of age, sex, and population differences. These results suggest that the EDAR gene plays a major role in determining hair thickness among various Asian populations.