title: Possible changes in the frequency of the human ABO blood groups in Iceland due to smallpox epidemics selection.
abstract: The hypothesis is put forward that the low frequency of A and high frequency of O blood group genes in the Icelandic human population is the result of a selective disadvantage of A during severe smallpox epidemics. The hypothesis is supported by data from India in 1965-6, which show a marked selective effect of a smallpox epidemic against the phenotypes A and AB (Vogel & Chakravartti, 1971). The conclusion is drawn that the present-day ABO blood group gene frequencies of the Icelandic population should be used with reservation as markers in the study of the origin of the Icelanders.
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D004196:Disease Outbreaks / Q000453:epidemiology*; D004198:Disease Susceptibility; D005787:Gene Frequency; D005819:Genetic Markers; D006801:Humans; D007055:Iceland; D012641:Selection, Genetic; D012899:Smallpox / Q000097:blood* / Q000453:epidemiology / Q000235:genetics
chemical_list: D000017:ABO Blood-Group System; D005819:Genetic Markers