Distribution of hereditary blood groups among Indians in South America. 3. In Bolivia

Blood samples were procured from the following populations of putatively pure Indians in Bolivia: 503 Aymará from the Altiplano and Yungas, 30 Chama, 11 Tacana, 14 Chácobo, 109 Itonama, 67 Moré, and 27 Sirionó from the Beni and lowland rainforest. Erythrocytes from these 761 specimens were tested for antigens in the A-B-O, M-N-S-s, P, Rh-Hr, Lutheran, Kell-Cellano, Lewis, Duffy, Kidd, and Diego systems, and for the Wright agglutinogen. The serum samples were tested for haptoglobins and transferrins; and hemolysates were prepared and examined for hemoglobin types. Results of these tests are presented as phenotypes and calculated gene frequencies on appropriate tables. A map is included to show the locations of the populations from which blood samples were obtained. Frequencies are generally high for the O gene, it being the only gene of the ABO system which appears in the Chama, Chácobo and Sirionó. The presence of A₁, A₂ or B genes in the Bolivian Indians is interpreted as being most probably of caucasoid introduction. Excepting the Sirionó the frequencies are high for M and low for N genes as is usual for Amerinds, the M gene being the only one detected in the Chama. The s gene frequency in high and the S low except in the small isolated Chácobo population in which S gene frequency is extremely high for Amerinds. Inbreeding and perhaps genetic drift in this small isolate may account for this aberrancy from normal. The Bolivian specimens presented the high frequencies for genes R¹ (CDe) and R² (cDE) and the low frequencies for genes r (cde) and R⁰ (cDe) usually observed in American Indians. The Lu^a factor was observed in only one of 120 Aymará at Santa Fe in the Yungas. The Lu^a factor, when observed in Amerinds, suggests foreign introduction of the responsible gene. Fy^a gene frequencies are consistently high and excepting the Aymará and Chama so also are Jk^a frequencies. Frequencies for the Diego (Di^a) factor vary from 3.70% in 27 Sirionó to 73.33% in 30 Chama. No K, Mi^a, Vw or Wr^a antigens were demonstrable in the Indian blood samples from Bolivia. Phenotypes and calculated gene frequencies for haptoglobins and transferrins are presented. All Bolivian Indian bloods tested electrophoretically contained only hemoglobin (A) as a major component.