STR polymorphisms of the Henan population and investigation of the Central Plains Han origin of Chaoshanese

Regional difference in the susceptibility of non-alcoholic fatty liver disease in China

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is a global health problem with high geographic heterogeneity. We aimed to investigate regional-specific concomitant rate of NAFLD and quantitative relationship between liver fat content (LFC) and glucose metabolism parameters in representative clinical populations from six provinces/municipalities of China.

RESEARCH DESIGN AND METHODS

A total of 2420 eligible Han Chinese were enrolled consecutively from 10 clinics of obesity, diabetes and metabolic diseases located at six provinces/municipalities of China, and divided into North (Tianjin, Shandong and Heilongjiang) and South (Shanghai, Jiangsu and Henan) groups according to their geographical latitude and proximity of NAFLD concomitant rate. LFC was assessed by a quantitative ultrasound method. Multivariate regression models and analysis of covariance were used to assess the regional difference in the risk of NAFLD.

RESULTS

The concomitant rate of NAFLD was 23.3%, 44.0% and 55.3% in individuals with normal glucose tolerance (NGT), pre-diabetes and diabetes, respectively. A higher concomitant rate of NAFLD was found in the participants from the North comparing with the South group, regardless of glucose metabolism status (34.7% vs 16.2% in NGT, 61.5% vs 34.7% in pre-diabetes and 67.1% vs 48.1% in diabetes). This regional difference remained significant after adjustment for age, gender, alcohol drinking, cigarette smoking, confounding metabolic parameters and liver enzymes. For any given blood glucose, participants from the North had higher LFC than those from the South group.

CONCLUSIONS

Half of Han Chinese with pre-diabetes/type 2 diabetes had NAFLD, and the individuals from the North cities were more susceptible to NAFLD.

Genetic composition of Teochew population in Chaozhou revealed by 19 STR loci: population polymorphism and interpopulation comparisons

Aim: To investigate the genetic polymorphisms of 19 STR loci in the Teochew population of Chaozhou. Subjects and methods: Nineteen STR loci of 631 unrelated Teochew people in Chaozhou were detected by using the AGCU Expressmarker 20 kit. Results: The allele frequency ranged from 0.0008-0.5577. The combined power of discrimination and combined probability of excluding paternity is over 0.999,999,999,999,999,999,999,999,999,999 and 0.999,999,992,549,546, respectively. The principal component analysis based on the 11 shared STR loci showed the Teochew population was most genetically related to the Fujian Han population. Conclusion: The results demonstrate the set of 19 autosomal STRs could provide robust genetics information for individual identification, paternity testing and human genetics research in the Teochew population.

Mitochondrial DNA haplogroup confers genetic susceptibility to nasopharyngeal carcinoma in Chaoshanese from Guangdong, China

Recent studies have shown association of mtDNA background with cancer development. We analyzed mitochondrial DNA (mtDNA) control region variation of 201 patients with nasopharyngeal carcinoma (NPC) and of 201 normal controls from Chaoshan Han Chinese to discern mtDNA haplogroup effect on the disease onset. Binary logistic regression analysis with adjustment for gender and age revealed that the haplogroup R9 (P = 0.011, OR = 1.91, 95% CI = 1.16-3.16), particularly its sub-haplogroup F1 (P = 0.015, OR = 2.43, 95% CI = 1.18-5.00), were associated significantly with increased NPC risk. These haplogroups were further confirmed to confer high NPC risk in males and/or individuals ≥ 40 years of age, but not in females or in subjects <40 years old. Our results indicated that mtDNA background confers genetic susceptibility to NPC in Chaoshan Han Chinese, and R9, particularly its sub-haplogroup F1, is a risk factor for NPC.

Ascertaining the role of Taiwan as a source for the Austronesian expansion

Taiwanese aborigines have been deemed the ancestors of Austronesian speakers which are currently distributed throughout two-thirds of the globe. As such, understanding their genetic distribution and diversity as well as their relationship to mainland Asian groups is important to consolidating the numerous models that have been proposed to explain the dispersal of Austronesian speaking peoples into Oceania. To better understand the role played by the aboriginal Taiwanese in this diaspora, we have analyzed a total of 451 individuals belonging to nine of the tribes currently residing in Taiwan, namely the Ami, Atayal, Bunun, Paiwan, Puyuma, Rukai, Saisiyat, Tsou, and the Yami from Orchid Island off the coast of Taiwan across 15 autosomal short tandem repeat loci. In addition, we have compared the genetic profiles of these tribes to populations from mainland China as well as to collections at key points throughout the Austronesian domain. While our results suggest that Daic populations from Southern China are the likely forefathers of the Taiwanese aborigines, populations within Taiwan show a greater genetic impact on groups at the extremes of the current domain than populations from Indonesia, Mainland, or Southeast Asia lending support to the "Out of Taiwan" hypothesis. We have also observed that specific Taiwanese aboriginal groups (Paiwan, Puyuma, and Saisiyat), and not all tribal populations, have highly influenced genetic distributions of Austronesian populations in the pacific and Madagascar suggesting either an asymmetric migration out of Taiwan or the loss of certain genetic signatures in some of the Taiwanese tribes due to endogamy, isolation, and/or drift.

Dominant contribution of northern chinese to the paternal genetic structure of Chaoshanese in South China

We investigated the Y chromosome of various Chinese populations to determine the patrilineal origin of the Chaoshanese population. Admixture analysis of six specific Y short tandem repeat (STR) loci in 6,292 individual samples taken from 51 populations, including Chaoshanese and Minnanese of our earlier studies, showed that over 85% of the Chaoshanese Y chromosomes were derived from the Central China Han (M (RH): 0.8614; M (BE): 1.1868 ± 0.2054), and a very small portion were from the southern aborigines. These results support a Central China Han origin of the Chaoshanese and additionally reveal that males from the Central China Han were the predominant contributor to the patrilineal genetics of the Chaoshanese. A phylogenetic tree and analysis of molecular variance signified a strong association between Y chromosomes of Chinese populations and their linguistic affiliations, revealing a coevolution of Y chromosome diversity and languages in East Asia.