The frequency of inactive sucrase-isomaltase variant in indigenous populations of Northeast Asia

Abstract

The AG dinucleotide deletion at the rs781470490 locus of the sucrase-isomaltase gene (SI gene), common in the Eskimo people of Canada and Greenland, was screened in the indigenous populations of Northeast Asia (among Chukchi, Koryaks, Evens, and Evenks). Deletion was detected at the frequency of 14.3% (95% confidence interval (CI): 4.7–33.6%) in Chukchi, 7.3% (95% CI: 3.4–14.3%) in Koryaks, and 3.5% (95% CI: 1.3–8.5%) in Evens. Since the deletion at the rs781470490 locus leads to premature termination of the sucrase-isomaltase synthesis and, accordingly, to the appearance of an inactive form of the enzyme, it is suggested that its wide prevalence in populations of the Far North of America and Asia is associated with adaptation to an Arctic diet deficient in sucrose.