ETHNIC-DIFFERENCES IN INTERFERON-ALPHA ALLELE FREQUENCIES

Interferon-alpha (IFN-alpha) is a protein family controlled by altoget her 26 different IFN-alpha genes. We have previously described an SspI polymorphism in the IFN A17 gene and an association between the SspI A2 allele and nasopharyngeal cancer. In this paper we present data on ethnic differences with respect to IFN A17 SspI allele frequencies. Th us the frequency of the SspI A1 allele was high in two different Chine se populations (51 and 48%, respectively) and much lower (11%) in Swed es. Intermediate values were found in African Blacks (32%), Indians (2 5%), Saamis (29%) and Finns (24%). The very pronounced differences bet ween major ethnic groups make the IFN A17 SspI polymorphism a very inf ormative anthropological marker system and suggest that it may be bala nced and maintained by natural selection.