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The ethnic group Shuar is located in Ecuador. To identify their genetic composition, 46 ancestry-informative insertion deletion markers (AIM-INDELs) were used. Also, characterization of 15 tandem repeats (STRs) in the AmpFISTR Identifiler Kit were applied. Forensic parameters showed a matching probability of 0.1535, a power of discrimination of 0.8465, a polymorphism information content of 0.6584, probability of exclusion of 0.415 and a typical paternity index of 1.78. The Shuar are not influenced by admixture population events, being a Native American group 98.7%, along with a genetic diversity of 0.699346+/-0.356964.

The perception of taste is determined by several factors, including genetics, which at the same time is related with the diet and diseases in different populations. We aimed to identify the frequency of six single nucleotide polymorphisms (rs307355, rs35744813, rs713598, rs1726866, rs10246939 and rs11091046) involved in the perception of sweet, bitter and salty flavor in Ecuadorian mestizo population. It was found that the presence of the T allele of rs307355 and rs35744813 is associated with decreased ability of subjects to carry out specific discrimination of sweetness, this is particularly interesting given the correlation found (p = 0.0022) between sucrose perception and family history of cancer and diabetes. Furthermore, rs713598, rs1726866 and rs10246939 do not influence the ability to perceive the bitter taste. Concerning the perception of the salty taste, rs11091046 does influence the capacity of detecting it more easily. This theoretical knowledge of the genetic influence on taste perception can contribute to the understanding of eating habits and their impact on human health.

Fifteen autosomal STRs were analyze in order to elucidate the differences between low and high land Ecuadorian population. Seven Ecuadorian geographic areas (Tisaleo-Mocha, Canar, Quito, Rocafuerte, Santa Rosa, Guayaquil and Lago Agrio) from different altitude were selected for the study. After the analysis, little genetic distances were observed between all cities, the more distant cities (FST = 0.02354) were Rocafuerte at an elevation of 17 m.a.s.l. and Quito at 2850 m.a.s.l. and the similar cities (FST = 0.00033) were Rocafuerte (17 m.a.s.l.) and Santa Rosa (10 m.a.s.l). In conclusion, there is not a great genetic distance in the 15 STRs reported in high and low land Ecuadorian population, therefore previously reported frequencies could been used in identification and paternity cases under analysis.

Congenital insensitivity to pain with anhidrosis (CIPA) is an extremely rare autosomal recessive disorder characterized by self-mutilating behavior, unexplained fever, inability to sweat and intellectual disability. CIPA pathogenesis is associated with genetic loss-of-function mutations of the NTRK1 gene, which is auto phosphorylated activating intracellular signaling transduction such as cell survival, growth and differentiation. CIPA occurs with an incidence of 1 in 125 million newborns, and only some hundreds of cases have been reported worldwide. Most of cases have been reported in Asian countries. Here, we estimate the ancestral proportions of a family with consanguinity background affected with CIPA, who carries the missense pathogenic mutations rs80356677 (Asp674Tyr) in the kinase domain of NTRK1 and rs324420 (Pro129Thr) in the FAAH gene. The ancestral proportion was calculated through 45 ancestry informative markers (AIMs) and the comparison was done through the Human Genome Diversity Project panel. The resulting allele frequencies in CIPA family indicate a prevalence of the Native American ancestral component with 87.9%, and minor proportion for the European (8.9%) and African (3%) components. In conclusion, the genetic variations expressing CIPA in a Native American Ecuadorian family could have been caused by the insertion of certain genetic characteristics, which have been passed down from common ancestors as consequence of migration towards South America.

This study presents mitochondrial data from 55 unrelated individuals from two Ecuadorian Shuar communities: Kumbatza and Yukateis. Maternal linage was determined by analyzing the two mtDNA hypervariable regions: HRVI and HRVII. It was shown that the Shuar population exhibited the haplogroup B. This demonstrates that Shuar group is a conserved population with no mixing with the European and African diaspora populations.

Ecuador has various regions at different altitudes. It is known that at high altitudes, organisms experience multiple stressors, including exposure to ultraviolet (UV) radiation. The UV radiation exposure increases when getting closer to the Equator line. Consequently, cities in the Ecuadorian inter-Andean region and located at 2,800-3,000 m above sea level (masl) are exposed to UV levels approximately 40% higher than those of the lowlands. UV light is a carcinogen that causes mutations, DNA damage and cellular apoptosis. However, the XPC, XPD and XPG genes encode proteins that repair DNA caused by UV radiation. The aim of this study was to evaluate the distribution of three polymorphisms (rs2228001, rs13181 and rs17655) involved in the response to the damage caused by UV radiation in the Ecuadorian populations of high and low altitudes, and thus, correlate the ancestral proportions of these populations. Results showed that the behavior of both groups located at different altitudes is similar. The ancestry of these groups exhibited that the Native American component prevails, and the European and African component varies.