Interferon-inducible transmembrane protein 3 (IFITM3) participates in the defense against viral infections. This study identified and compared the frequency of the IFITM3 rs12252 polymorphism in 410 individuals in western Mexico. The western Mexican allelic frequencies (frequency of the "C" allele = 0.18) differ from some American, East Asian and European populations. © 2018 John Wiley & Sons Ltd.