RESUMO
We performed a genome-wide association study with 23,465 microsatellite markers to identify genes related to adult height. Selective genotyping was applied to extremely tall and extremely short individuals from the Khalkh-Mongolian population. Two loci, 8q21.13 and 15q22.33, which showed the strongest association with microsatellites were subjected to further analyses of SNPs in 782 tall and 773 short individuals. The most significant association was observed with SNP rs2220456 at 8q21.13 (P = 0.000016). In the LD block at 15q22.32, SNP rs8038652 located in intron 1 of IQCH was strongly associated (P = 0.0003), especially the AA genotype of the SNP under a recessive model was strongly associated with adult height (P = 0.000046).
Assuntos
Estatura/genética , Mapeamento Cromossômico , Cromossomos Humanos Par 15 , Cromossomos Humanos Par 8 , Ligação Genética , Locos de Características Quantitativas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Frequência do Gene , Genética Populacional , Genoma Humano , Genótipo , Humanos , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Mongólia , Polimorfismo de Nucleotídeo ÚnicoRESUMO
The Khoton Mongolian population is a small and relatively isolated ethnic group residing predominantly in the northwestern part of Mongolia. A recent genetic study of the Y chromosome revealed that the major Mongolian ethnic groups have a relatively close genetic affinity to populations in the northern part of East Asia, while the Khoton population reflected an apparent genetic differentiation from the other Mongolian populations. To further investigate the genetic features of the Khoton and the other Mongolian populations, we analyzed the single nucleotide polymorphisms (SNPs) in the Xq13.3 region, which is thought to have an extremely low level of recombination in the human X chromosome. We found that the frequency distribution of Xq13.3 haplotypes in the Khoton population was substantially different from those in three other Mongolian populations (Khalkh, Uriankhai, and Zakhchin). The same relationship was also revealed by the results from the population tree and principal-component (PC) analysis based on the allele frequencies. These results are largely consistent with the hypothesis that the Khoton population descended from a nomadic tribe of Turkish origin, which has been supported by previous anthropological, historical, and Y-chromosome studies. However, the population structure analysis produced an additional finding, namely, that the Khoton population is likely to be an admixed population.
Assuntos
Alelos , Cromossomos Humanos X/genética , Haplótipos/genética , Povo Asiático , Cromossomos Humanos Y/genética , Frequência do Gene , Genética Populacional/métodos , Humanos , Mongólia , Polimorfismo de Nucleotídeo Único , Recombinação Genética/genéticaRESUMO
About 20 ethnic groups reside in Mongolia. On the basis of genetic and anthropological studies, it is believed that Mongolians have played a pivotal role in the peopling of Central and East Asia. However, the genetic relationships among these ethnic groups have remained obscure, as have their detailed relationships with adjacent populations. We analyzed 16 binary and 17 STR polymorphisms of human Y chromosome in 669 individuals from nine populations, including four indigenous ethnic groups in Mongolia (Khalkh, Uriankhai, Zakhchin, and Khoton). Among these four Mongolian populations, the Khalkh, Uriankhai, and Zakhchin populations showed relatively close genetic affinities to each other and to Siberian populations, while the Khoton population showed a closer relationship to Central Asian populations than to even the other Mongolian populations. These findings suggest that the major Mongolian ethnic groups have a close genetic affinity to populations in northern East Asia, although the genetic link between Mongolia and Central Asia is not negligible.