Apparent Afro-Asiatic, Southern Asian, & European HLAs in Indigenous American Populations

http://www.neara.org/Guthrie/lymphocyteantigens01.htm

Human Lymphocyte Antigens: Apparent Afro-Asiatic, Southern Asian, &
European HLAs in Indigenous American Populations
by James L. Guthrie

Abstract

Studies have shown that the number of human lymphocyte antigen (HLA)
alleles characteristic of indigenous American populations is
relatively small, and that some isolated South American tribes possess
only a few types that are common throughout the Americas. But other
groups, especially those near sites of former Mesoamerican and Andean
urban societies, exhibit HLA alleles that are rare in America but
common in certain Afro-Asiatic, South Asian, and European populations.
These unexpected genes account, on the average, for 6-7% of the
American HLA total, but range as high as 24%.

The atypical genes are postulated to have been acquired by
assimilation of foreign populations at various times after initial
colonization of the hemisphere but prior to the sixteenth-century
influx of Europeans and Africans, because they suggest gene-flow from
places some scholars claim to have been in ancient contact with the
Americas, such as North Africa and Southeast Asia. The occurrence of
parallel anomalies in blood groups such as Rhesus, Kell, and Duffy, as
well as in serum proteins such as transferrin and immunoglobin,
supports this interpretation to some degree, but the small number and
poor distribution of samples in all systems, including HLA, preclude
conclusive results. Other explanations are considered possible but
less likely. Key Words: Genetics, Americas, Migrations,
Pre-Columbian.

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