Genetic Polymorphism of Mitochondrial DNA in Dong,Gelao,Tujia,and Yi Ethnic Populations from Guizhou,China

To reveal the genetic structures and relationships of the four ethnic populations from the maternal inheritance and explore the origins and migrations of nationalities, the genetic polymorphism of mtDNA in Dong, Gelao, Tujia, and Yi populations from Guizhou was studied by direct sequencing of hypervariable segment Ⅰ （HVS Ⅰ ） and PCR-RFLP of coding region. Thirty-seven （sub-） haplogroups were identified in the classification tree of mtDNA haplogroups. Haplogroup distributions and principal component （PC） analysis showed that the Dong has high frequencies of south-prevalent haplogroups, which indicates that it is a typically southern population. The Yi harbors high frequencies of the south-prevalent and northern-prevalent haplogroups, which demonstrates that it inherits the maternal characteristics from both southern and northern populations. The Yi and Gelao cluster together, the reason for which might be that their ancestries frequently underwent gene exchanges and mixtures.

Melanocortin-1 receptor gene variants in four Chinese ethnic populations

There is strong relationship between melanocortin-1 receptor (MCIR) gene variants and human hair color and skin type. Based on a sequencing study of MC1R gene in 50 individuals from the Uygur, Tibetan, Wa and Dai ethnic populations, we discuss the occurrence of 7 mc1r variants consisting of 5 nonsynonymous sites (Val60Leu, Arg67Gln, Val92Met, Arg163Gln and Ala299Val) and 2 synonymous sites (C414T and A942G), among which C414T and Ala299Val were reported for the first time. Confirmation and analysis were the made of 122 individuals at three common point mutations (Val92Met, Arg163Gln, A942G) using PCR-SSCP. The frequency of Arg163Gln variant varies in the four ethnic populations, with percentage of 40%, 85.0%, 66. 2% and 72.7%, respectively, while those of Val92Met and A942G are roughly similar in these four populations. The different environments, migration and admixture of various ethnic groups in China might have impact on the observed frequency of Arg163Gln.

Development of a 9-locus X-STR Multiplex PCR System for Genetic Analysis of Three Ethnic Populations in China

X-chromosome short tandem repeats（X-STR） analysis has been confirmed to be effective for kinship testing such as in deficiency paternity cases. The aim of this study was to develop a new multiplex polymerase chain reaction（PCR） system that can simultaneously amplify 9 X-STR loci（GATA172D05, DXS10159, DXS6797, HPRTB, DXS10079, DXS6789, DXS9895, DXS10146 and GATA31E08） in the same PCR reaction, and to obtain the database of the 9 X-STR loci in three ethnic populations in China. The genetic data of 815（404 females and 411 males） unrelated Han Chinese from Hubei province, and Yi and Zhuang Chinese from Yunnan province were analyzed by using this multiplex system. The results showed that a total of 93 alleles for all these loci were found, and 7 to 20 alleles for each locus were observed. All of the analyzed loci were in agreement with Hardy-Weinberg equilibrium after Bonferroni correction in the three studied populations. The polymorphism information content（PIC） and power of discrimination（PD） in females were 0.6566–0.8531 and 0.8639–0.9684, respectively. Pairwise comparisons of allele frequency distribution showed significant differences in the most of these loci between different populations. The results indicate that this multiplex system is very useful for forensic analysis of different ethnic populations in China.

Family Planning in Yunnan's Ethnic Populations

MOST people know about China’s family planning policy, which began in the 1980s. In view of the differences in culture and living environments between the majority Han Chinese and peoples of other ethnicities, the Central government decided that local governments of provinces and cities with minority nationalities could be given leeway to design more specific and more flexible methods of family planning.

Infra-tentorial brain tumor subtypes in children and adults--surgical outcome in an ethnic population with a single regional tertiary center

Background:To analyze clinically and radiologically the surgical outcome like residual disease,progression of disease,recurrence,disabilities,event-free survival(EFS),and mortality of different infra-tentorial tumor subtypes in children and adults of a strictly non-migratory and ethnic population.Methods:The 410 histologically proved,out of 589,infra-tentorial brain tumor patients were analyzed clinically and by the imaging post-surgically in a single tertiary center for an ethnic region.In this analytico-observational study,retrospectively postoperative records of 589 infra-tentorial brain tumors from November 1998 to December 2018(20 years)were retrieved,scrutinized,and compiled.The post-operative clinic-radiological records of 410 patients with proved histopathological examination results were included.Statistical law of variance was applied where-ever necessary.Results:The 63.2%of the all 410 operated infra-tentorial brain tumors were males while females predominated in meningiomas and pineoblastomas.About 31.7%infra-tentorial tumors were children(below 18 years).About 54.1%cases were histologically malignant.The residual tumors comprised 40.2%and symptoms of disease-progression occurred in 10.9%.The tumor recurrence occurred in 14.3%while 6.0%patients developed severe disability.The overall mortality was 11.4%but 18.9%in malignant tumors.The event-free survival(EFS)for all the patients was 66.0%,patients with malignancies had 47.7%and benign group had 87.7%.Conclusion:The study,surgical outcome of infra-tentorial brain tumor subtypes in children and adults(approx.1/3rd of patients being children),conducted in a tertiary center at a remote land-locked location with non-migratory ethnic population as its catchment area,has a significant epidemiological value for the community and the region.