Apolipoprotein H genetic variability in the population of Krk Island, Croatia.

Apolipoprotein polymorphisms are emerging as suitable markers for the study of the formation of human populations. In contrast to the data available for apolipoprotein E, the data regarding apolipoprotein H (protein, apoH; gene, APOH) variations are only beginning to accumulate. By blood plasma isoelectric focusing and immunoblotting, we analyzed the distribution of apoH phenotypes in 397 individuals (192 males; 205 females) from seven villages of an autochthonous population of the eastern Adriatic island of Krk. APOH allele frequencies were: APOH2 = 0.877, APOH3 = 0.098, APOH*1 = 0.025, with the majority of the sample being homozygous. No significant differences between villages were observed. When these data were compared to those of other populations studied so far, a significant association between APOH allele frequencies and latitude was observed. We hypothesize that this association reflects differences in diet composition across different climatic zones.