Blood group, red cell, and serum protein variation in the Cabecar and Huetar, two Chibchan Amerindian tribes of Costa Rica

Abstract

Genetic variation, using blood groups and red cell and serum proteins, was surveyed in the Cabecar of Chirripo and the Huetar of Quitirrisi, Costa Rica. Thirty-nine loci were screened in a sample of 91 Cabecars and 40 loci in 45 Huetars. Twenty-seven loci were monomorphic in the Cabecar and 30 in the Huetar. The proportions of polymorphic loci (P), out of 34 studied by electrophoresis, were 0.235 and 0.177, respectively. Estimated gene diversities (H) of the polymorphic loci were 0.050 in the Cabecar and 0.053 in the Huetar. Two polymorphisms, reported until now in Costa Rican and Panamanian Chibchan groups only, occurred at very high frequencies: TF*DGUA = 0.357 in the Cabecar, the highest frequency ever reported, and 0.033 in the Huetar; and PEPA*F, which reached 0.26 in the Cabecar and 0.29 in the Huetar. Nei's genetic distances and trees (two methods) were used to compare them to seven other Chibchan tribes of Costa Rica. The results placed both the Cabecar of Chirripo and the Huetar closer to the Talamancan Tribes (Bribri and Cabecar). This was an unexpected result for the Huetar, since linguistic studies suggested a closer relationship to the Guatuso. GST, DST, RST, and Dm for three Cabecar subpopulations (Atlantic, Chirripo, and Pacific) doubled their values compared to estimates based on comparison of only two subpopulations: Atlantic and Pacific. Total genetic diversity considering just the three Cabecar subpopulations resembled that obtained including them plus six other Chibchan populations of Costa Rica.

Relevance of the ancestry for the variability of the Drug-Metabolizing Enzymes CYP2C9, CYP2C19 and CYP2D6 polymorphisms in a multiethnic Costa Rican population

“…The observed low frequency of the decreased-activity allele CYP2C9*2 in the most Amerindian populations from Costa Rica (Bribri, Cabécar, Maleku and Guaymí) (Azofeifa, Ruiz, & Barrantes, 2001), is consistent with other studies on North-and South-Amerindians, which reported frequencies from 0 to 4.8 % for this allele (Céspedes-Garro et al, 2015). Noteworthy, the high CYP2C9*2 frequency in the Huetar (8.3 %) is similar to that of the Costa Rican admixed population (7.7 %), in agreement with reports that estimate that the Huetar groups have European and African admixture as high as 3.9 to 32.9 % (Barrantes, 1993;Santos, Ward, & Barrantes, 1994;Bieber, Bieber, Rodewald, & Barrantes, 1996;Azofeifa et al, 2001;Ruiz-Narváez et al, 2005).…”

Molecular Variability of the 16p13.3 Region in Amerindians and its Anthropological Significance

“…Central and South Amerindians showed no significant differences. But in Central America only the two most common haplotypes (HP5 and HP1) were found, and this low genetic variability may have occurred because of isolation followed by a population reduction (Barrantes et al 1990; Azofeifa et al 2001). The difference observed among populations within groups (∼15%) was probably due to genetic structure within South America.…”