HLA genes in Uros from Titikaka Lake, Peru: origin and relationship with other Amerindians and worldwide populations

Abstract

Uros population from the Titikaka Lake live in about 42 floating reed ('totora') islands in front of Puno City (Peru) at a 4000 m high altiplano. They present both an mtDNA and a human leucocyte antigen (HLA) profile different from the surrounding populations: mtDNA A2 haplogroup is common to Uros and Amazon forest lowland Amerindians. HLA genetic distances between populations have been calculated and neighbour-joining dendrograms and correspondence analyses were carried out. Approximately 15 006 HLA chromosomes from worldwide populations have been used for comparisons. Only eight HLA-A alleles have been found, three of them accounting for most of the frequencies. The same phenomenon is seen for HLA-B, HLA-DRB1 and HLA-DQB1 alleles: a few alleles (3, 4 and 3, respectively) are present in most individuals. The presence of HLA-B*4801 and HLA-DRB1*0901 alleles in a relatively high frequency (although not the most frequent alleles found) is a characteristic shared with Asians and some populations from the Andean altiplano. Three specific Uros haplotypes have been found among the most frequent ones: HLA-A*680102-B*3505-DRB1*0403-DQB1*0302; HLA-A*2402-B*1504-DRB1*1402-DQB1*0301; and HLA-A*2402-B*4801-DRB1*0403-DQB1*0302. The present study suggests that Uros may have been one of the first populations from the shores of the Titikaka Lake coming from the Amazonian forest, which might have given rise to other later differentiated ethnic group (i.e. Aymaras). Uros HLA profile is also useful to study genetic epidemiology of diseases linked to HLA and to construct a future transplant waiting list by adding up regional lists in order to get a bigger pool for transplanting with better HLA matching.

The Origin of Amerindians and the Peopling of the Americas According to HLA Genes: Admixture with Asian and Pacific People

“…The genetic relatedness among Amerindians, Na-Dene, Eskimos, Asians, Negroids, Europeans and Polynesians are determined by calculating the genetic distances between populations (DA), using HLA-DRB1 allele frequencies. Amerindians cluster together and separated from the rest of the World populations [14,34,35,37]. …”

“…These relationships are calculated in n dimensions and represented in two dimensions. Circles represent an approximate grouping of populations [14,34,35,37]. …”

“…Also, we have studied the following Amerindian ethnic groups: Seri, Mixe, Mixtecans, Zapotecans, Guaranis [23], Lakota Sioux [24], Mazatecans [25], Teeneks [26], Mayans [27], Kogi, Arsario, Arhuacs, Wayu [28], Cayapa [29], Lamas [30], Aymaras [31], Quechuans [32], Terena Indians [33], Xavantes, Mayos [34], Uros [35], Nahuas [36], Tarahumaras [37], Toba Pilaga, Mataco Wichi, Eastern Toba [15], Mexican Mestizos and Jaidukama (unpublished results) and also Aleuts [14]. …”

HLA Class I and Class II Conserved Extended Haplotypes and Their Fragments or Blocks in Mexicans: Implications for the Study of Genetic Diversity in Admixed Populations

“…Principal Components Analysis (PCA) for 38 populations with HLA-B data available was performed using the IBM SPSS Statistics 19 software ( IBM Corporation, Armonk, NY, USA ) to analyse the distribution of HLA-B alleles in human groups of the proposed ancestries, Figure 1 . PCA included population data of Ireland [20], NW of England [61], Germany [62], Austria [63]; Spain, Italy, United Kingdom [64], France [65], Gypsy from Andalucía (Spain; data collected by López-Nevot et al ) [14], Azores Terceira Island [66], Forro from São Tomé Island [67], Beti from Cameroon [68], Bandiagara from Mali, Lusaka from Zambia, Luo and Nandi from Kenia [69], Mandeka from Senegal [70], Guinea Bissau [71], Aleut from Bering Island (Russia) [72], center of Japan [73], a cord blood bank of Tzu Chi Foundation (Taiwan) [74], Han from southern China [60], north India [75], Kensiu from Malasya [76], Kinh from Vietnam [77], Tarahumara from northern Mexico [17], Native Americans from Gila River (USA) [78], Yu’pik from Alaska (USA) [79], Mixtec, Zapotec, and Mixe from Oaxaca (Mexico) [16], Seri from Sonora (Mexico) [80], Navajo from New Mexico (USA) [81], Uro from Titikaka Lake (Peru) [82], and Toba from Rosario (Argentina; data collected by Cintia Marcos et al ) [14]. Also, two admixed populations from Mexico were included: a “Mexican Mestizo” sample [83] and a sample from Guadalajara City, western Mexico [23].…”

The Genetic History of Indigenous Populations of the Peruvian and Bolivian Altiplano: The Legacy of the Uros

“…However, few genetic studies have been conducted with Uros communities. A previous study of HLA profiles [16] suggested an ancient connection between the Uros from Puno and Amazonian ethnic groups, following an old hypothesis of connection between Uruquilla (original language of the Uros) and the Arawak linguistic branch [7], [8]. Other genetic studies using mtDNA [17], [18] suggested that the Uros from Lake Titicaca still conserve part of their own ancient genetic background, while also forming a heterogeneous group.…”