The HLA-DRB1*0404, DRB4*0101, DQA1*0301, DQB1*0302 REPRESENTS AN ANCESTRAL
HAPLOTYPE IN AMERINDIANS. ANALYSIS OF 1512 INDIVIDUALS BELONGING
TO 24 DIFFERENT TRIBES IN COLOMBIA.
J. J.Yunis1. and E. Yunis1.
1Instituto de Genética, Universidad Nacional de Colombia.
We have analyzed 1512 individuals belonging to 24 different
Amerindian tribes of Colombia. 22 of the tribes studied belong to 8 different
linguistic families (Chibcha, Tukano, Karib, Maku, Guahibo, Quechua Arawak
and Choco) and two lack classification at the moment. A Frequency above
5% for the HLA-DRB1*0404, DRB4*0101, DQA1*0301, DQB1*0302 haplotype was
found in 12 of the 24 Amerindian groups, and above 1% in 15 Amerindian
Tribes. This haplotype was absent from 9 Amerindian groups. The highest
frequency was found in the Ingano tribe (24.3%) a Quechuan speaking group,
followed by the Guambiano (21%), Piratapuyo (20.6%), Tucano (17.20%), Desano
(16.30%), Nukak (15.80%), Cubeo (14.7%), Paez (10.20%), Curripaco (6.5%),
Guanano (6.1%), Piapoco (5.7%), Puinave (5.3%), Wayuu (1.6%), Guayabero
(1.4%) and Embera (1.2%). These results are unlikely due to genetic admixture
with Caucasian. This conclusion is based on: 1) Several of the Amerindian
tribes analyzed here, are isolated groups living in the Amazonian Jungle
(Tucano, Desano, Piratapuyo, Guanano, Cubeo, Puinave, Nukak, Piapoco, Curripaco,
Guayabero. 2) The Nukak tribe had the first reported contact with the mestizo
population in Colombia in 1988, thus a very isolated tribe. 3) Based on
blood group typing, the Wayuu population has a high degree of admixture
with Caucasians (around 33%), yet the frequency for the DRB1*0404 carrying
haplotype was only 1.6%. 4) The Ingano and Guambiano tribes have some admixture
with Blacks but not with Caucasians, based on blood group typing. Of interest
is the finding that none of the 6 Chibchan speaking groups carry this haplotype
(Arhuaco, Kogui, Arzario, Chimila, Bari, Tunebo) and had marginal frequencies
in the Choco speaking groups (Embera) and Guahibo speaking groups (Guayabero),
while it was present in the Tukano, Arawak and Maku linguistic groups that
are mainly found in the Amazonian Region of South America.