Typing of Amerindian Kichwas and Mestizos from Ecuador with the SNPforID multiplex.

A total of 119 unrelated individuals from two of the major ethnic groups in Ecuador were typed for 49 of the autosomal single nucleotide polymorphisms (SNPs) in the SNPforID 52plex using the SNapShot(®) assay. Of the above, 42 samples originated from Mestizos (an admixed population) and the remaining 77 were from Native Amerindian Kichwas. We obtained full SNP profiles in all individuals and concordance of duplicated analyses. No deviation from Hardy-Weinberg equilibrium (HWE) was observed for any SNP in the Mestizo and Kichwa populations and only one and four pairs of loci, respectively showed significant linkage disequilibrium. A relatively low genetic diversity and global positive F(IS) value was observed in Kichwas. A statistically significant global F(ST) value was obtained when the two Ecuadorian populations were compared with populations in Spain, Portugal, Argentina, Denmark, Greenland, China, Somalia and Mozambique. All pairwise F(ST) values were statistically significant. A multi-dimensional scaling based on pairwise F(ST) values showed that the Kichwa population differed from all other populations investigated and that the Mestizos had an intermediate position between Kichwas and Europeans. An admixture analysis indicated that the greater contributor to the Mestizo population was the Kichwas (71.2%) compared to the European contribution. The combined mean match probability and mean paternity exclusion probability were 3.3 × 10(-17) and 0.998, respectively, for the Mestizo population and 3.3 × 10(-14) and 0.993, respectively, for the Kichwa population.

Hierarchical Y-SNP assay to study the hidden diversity and phylogenetic relationship of native populations in South America.

Studying the Y chromosomes of indigenous tribes of Ecuador revealed a lack of strategic SNP assays to examine the substructure of South American native populations. In most studies dealing with South American samples so far only the most common Y-SNP M3 of haplogroup Q was analyzed, because this is known to define a founder group in South America. Studies of SNPs ancestral to Q-M3 (Q1a3a) to confirm the results or the typing of Q subclades have often been neglected. For this reason we developed a SNaPshot assay, which allows first for a hierarchical testing of all main haplogroups occurring in South American populations and second for a detailed analysis of haplogroups Q and C thought having ancient Asian descent. We selected 16 SNPs from the YCC haplogroup tree and established two multiplexes. The first multiplex ("SA Major") includes 12 Y-SNPs defining the most frequent haplogroups occurring in South America (M42, M207, M242, M168, M3, M145, M174, M213, RPS4Y711, M45, P170, and M9). The second multiplex ("SA SpecQ") contains Y-SNPs of haplogroup Q, especially of the subclade Q-M3 (M19, M194, P292, M3, and M199). Within our Ecuadorian sample, haplogroup Q-M3 (xM19, M194, P292, and M199) was predominant, but we also found haplogroup E and R, which can be attributed to recent admixture. Moreover, we found four out of 65 samples, which were tested to be haplogroup C3* (C-M217) the modal haplogroup in Mongolians and widespread in indigenous populations of the Russian Far East as well as in Eastern Asia. This haplogroup is not known to be the result of recent admixture and has been found only one time before in South America. Since haplogroup C occurs in Asia and in North America (C3b or C-P39), we assume that these C-lineages are ancient as well. Therefore, we established a third multiplex ("SA SpecC"), which allows the further subtyping of haplogroup C, mainly of subclade C3 defined by the Y-SNP M217 (M407, M48, P53.1, M217, P62, RPS4Y711, M93, M86, and P39). Altogether, these three multiplexes cover the most frequent haplogroups in South America and allow for a maximal resolution of the Y-chromosomal SNP diversity in Amerindian population samples.

Sex-specific genetic admixture of Mestizos, Amerindian Kichwas, and Afro-Ecuadorans from Ecuador.

Three main ethnic groups live in the South American country of Ecuador: Mestizos, Amerindian natives, and African-derived populations, or Afro-Ecuadorans. Mestizos and Afro-Ecuadorans can be considered trihybrid populations containing genes originating in the Americas, Europe, and Africa, as is the case with equivalent populations in other Latin American countries. The proportion and the dynamics of the admixture process remain unknown. However, a certain sex asymmetry of the admixture process can be expected for historical reasons. We typed 11 Y-chromosome short tandem repeats (STRs) in these three ethnic groups to provide adequate allele and haplotype frequencies for forensic genetic purposes and to quantify admixture proportions in male lineages. In addition, a data set of 15 autosomal STRs in the same samples were reanalyzed for the same purpose. Contributions to Mestizo Y chromosomes were estimated to be 70% European, 28% Amerindian, and 2% African, whereas in autosomes the contributions were 19%, 73%, and 8%, respectively, which underlines the sexual asymmetry in mating, with Europeans contributing mostly males. European Y-chromosome haplotypes in Mestizos were similar to those in Spain. Moreover, about 10% of European Y chromosomes were found in the Amerindian Kichwa. As for Afro-Ecuadorans, their contributions to the male line are 44% African, 31% European, and 15% Native American; the last value is the highest percentage reported so far for an African-derived American group. Autosomal admixture was estimated as 56% African, 16% European, and 28% Amerindian.

Incidencia y hallazgos clínicos y de laboratorio sobre lupus eritematoso sistémico en varios hospitales de la ciudad de Quito / clinical Incidence and findings and of laboratory on sistémico erythematous lupus in several hospitals of the city of Quito

Expone que el Lupus Eritematoso fue descrito en 1851 por Sir William Osler, como una enfermedad autoinmune. Se la ha llamado "la enfermedad de las mil caras" debido a que con frecuencia su diagnóstico se vuelve difícil en etapas iniciales. El LES comienza frecuentemente en los años fértiles de la mujer, sin embargo, se ha descrito en individuos de ambos sexos de cualquier raza o nacionalidad, desde los 2 hasta los 97 años de edad. Se realizó un estudio retrospectivo de 53 pacientes con LES, en base a un análisis documental de los datos exsitentes en las historias clínicas, en un período de 3 años. La muestra fue tomada de 3 hospitales de Quito, se consideraron solo aquellas que tenían nota de ingreso, los análisis de laboratorio de rutina completo y la epicrisis. Se seleccionaron 31 variables, entre signos y síntomas y test laboratoriales para su estudio. Los resultados más importantes fueron: se encontró un 33.3 por ciento de los pacientes entre los 31 y 40 años; el 92 por ciento de los estudiados fueron mujeres, de las cuáles un 55 por ciento ha estado embarazada y ha tenido un parto cefalovaginal en un 78 por ciento de los casos...