Since the report on the association of FLG mutations with atopic dermatitis, genetic diversity of FLG mutation was intensively investigated for European and other ethnic populations. However, except for the well-established racial difference between European and Asian, detailed analysis on the genetic diversity and its clinical implication of FLG mutation for East Asian ancestry was not performed, yet.
Methods:
To gain additional insights about FLG mutations in East Asia, first, we summarized data related to FLG mutations across East Asian countries, and then analyzed geographic distribution of FLG mutations in the light of human migration history in East Asia, and finally, we investigated the association of FLG mutations with various clinical features of atopic dermatitis, evaluating the clinical significance of FLG mutations in East Asian atopic dermatitis patients.
Results:
Through the genealogical analysis on the genetic diversities found in FLG mutations across East Asia, we confirmed that the distribution of FLG mutations among East Asian populations was consistent with hypothetical waves of human migrations along the southeastern coast of Asia. At the same time, several FLG mutations revealed associations with well-characterized Y chromosomal markers of established migration-history, thus showing their value as promising ancestry informative markers. With respect to the clinical aspect of FLG mutation in East Asia, this study revealed both the similarity and difference between European and Asian. Similar to Europeans, FLG mutations were significant risk factor of atopic dermatitis for East Asian and palmar hyperlinearity was a useful clinical marker in screening carriers of FLG mutation, however, in contrast to European, FLG mutations do not increase the risk of concomitant asthma for East Asian.
Conclusions:
In conclusion, this study showed that genetic diversity of FLG mutation across East Asia was consistent with human migration history along the costal border of East Asia. In addition, this study revealed that there is both similarity and difference in the clinical implication of FLG mutation between European and Asian ancestry.