Tibetan Groups Research Articles

Tibetans exhibit lower hemoglobin concentration and decreased heart response to hypoxia during poikilocapnia at intermediate altitude relative to Han Chinese.

High-altitude populations exhibit distinct cellular, respiratory, and cardiovascular phenotypes, some of which provide adaptive advantages to hypoxic conditions compared to populations with sea-level ancestry. Studies performed in populations with a history of high-altitude residence, such as Tibetans, support the idea that many of these phenotypes may be shaped by genomic features that have been positively selected for throughout generations. We hypothesize that such traits observed in Tibetans at high altitude also occur in Tibetans living at intermediate altitude, even in the absence of severe sustained hypoxia. We studied individuals of high-altitude ancestry (Tibetans, n = 17 females; n = 12 males) and sea-level ancestry (Han Chinese, n = 6 females; n = 10 males), both who had been living at ∼1300m (∼4327ft) for at least 18 months. We measured hemoglobin concentration ([Hb]), hypoxic ventilatory response (HVR), and hypoxic heart rate response (HHRR) with end-tidal CO2 (PetCO2) held constant (isocapnia) or allowed to decrease with hypoxic hyperventilation (poikilocapnia). We also quantified the contribution of CO2 on ventilation and heart rate by calculating the differences of isocapnic versus poikilocapnic hypoxic conditions (Δ /ΔPetCO2 and ΔHR/ΔPetCO2, respectively). Male Tibetans had lower [Hb] compared to Han Chinese males (p < 0.05), consistent with reports for individuals from these populations living at high altitude and sea level. Measurements of ventilation (resting ventilation, HVR, and PetCO2) were similar for both groups. Heart rate responses to hypoxia were similar in both groups during isocapnia; however, HHRR in poikilocapnia was reduced in the Tibetan group (p < 0.03), and the heart rate response to CO2 in hypoxia was lower in Tibetans relative to Han Chinese (p < 0.01). These results suggest that Tibetans living at intermediate altitude have blunted cardiac responses in the context of hypoxia. Hence, only some of the phenotypes observed in Tibetans living at high altitude are observed in Tibetans living at intermediate altitude. Whereas blunted cardiac responses to hypoxia is revealed at intermediate altitudes, manifestation of other physiological adaptations to high altitude may require exposure to more severe levels of hypoxia.

Online LC-ESI-MS/MS comparative analysis of N/O-glycopatterns in human colostrum from different ethnic groups in Northwest China

Human milk oligosaccharides, including free oligosaccharides and glycoconjugates, exert a key role in neonatal health and development. Changes in free oligosaccharides of milk from different ethnic groups have been documented. In this study, human milk was collected from Han, Hui, and Tibetan populations in northwest China, and differences in N/O-glycome among these three ethnic groups were systematically compared using online high-performance liquid chromatography-tandem mass spectrometry. Among the 63 detected N-glycans, 35 showed significant differences between the three ethnic groups (p < 0.05). Among the 70 detected O-glycans, four neutral O-glycans and six acidic O-glycans exhibited significant differences among the three ethnic groups (p < 0.05), with six acidic O-glycans reported for the first time. Overall, the extent of milk N/O-glycosylation was higher in the Han population than in the Hui or Tibetan groups. This trend was particularly pronounced for the main sialylated N/O-glycans. Except for sulfated O-glycans, which were higher in the milk from Tibetan mothers, the other types of N/O-glycans were present in similar proportions across all ethnic groups. Understanding the composition of N/O-glycans in human milk can help research on the structure-function relationship of glycans.

A Tibetan group from Ngawa Tibetan and Qiang Autonomous Prefecture, southwest China, is rich in genetic polymorphisms at 36 autosomal STR loci and shares a complex genetic structure with other Chinese populations

The Tibetan people are ancient and populous, constituting the seventh-largest of the fifty-five ethnic minority groups in China. The Ngawa Tibetan and Qiang Autonomous Prefecture (NTQAP), situated on the border of northwest and southwest China, has its distinct group relationships. Short tandem repeat (STR) is extremely polymorphic and extensively used in the application of forensic medicine and population genetics. However, it is not clear the genetic information including linkage disequilibrium (LD) by 36 autosomal STR (A-STR) markers in the Tibetan group from NTQAP. The Tibetan population from NTQAP of southwest China was examined for 36 A-STR loci in the research. Every marker across the 36 A-STR loci was consistent with Hardy–Weinberg equilibrium (HWE). The results of the calculation revealed that the total discrimination power (TDP) is 1–2.2552 × 10−42 and the cumulative probability of exclusion (CPE) is 1–1.3031 × 10−16. Subsequently, a total of 345 alleles with allelic frequencies ranging from 0.00382 to 0.55343 were identified, and the allelic numbers varied from 5 in both the TH01 and TPOX markers to 28 in the SE33 locus. The Ngawa Tibetan population, along with other Chinese populations, exhibited influences from historical factors and regional distribution, as indicated by the results of population genetics analysis. We thus first explored the genetic characteristics and correlated forensic parameters of the 36 A-STR markers in NTQAP to fill the gap in the Tibetan population. It was discovered that these 36 autosomal STR markers supplemented forensic STR databases and offered extremely valuable polymorphisms for Chinese forensic applications, such as parentage testing and personal identification. Moreover, the study would contribute additional information regarding the substructure and diversity in the Chinese population.

Unveiling the genetic landscape of high-altitude adaptive ethnic groups with polymorphic markers: Implications of comprehensive forensic appraisals and population genetic investigations

BackgroundDeletion/insertion polymorphisms (DIPs), a novel class of biomarker, have been widely utilized in forensic areas for individual identification, paternity tests, and ancestral origin inference due to its applicability to degraded samples and low mutation rates. Despite the availability of a well-established commercial kit, the Investigator® DIPplex kit (Qiagen), certain loci exhibit limited levels of polymorphisms in East Asian populations, particularly in Chinese populations. ObjectiveThis dissertation seeks to undertake a comprehensive evaluation about the forensic efficiency of a self-developed multiplex amplification system in high-altitude adaptive ethnic groups of China. Healthy unrelated Tibetan individuals residing in Tibet Autonomous Region and Qinghai Province were genotyped using previously reported 43 deletion/insertion polymorphism loci. Forensic statistical analyses including allele frequencies and forensic parameters were conducted in the two Tibetan groups, and the genetic relatedness of the studied groups with reference populations from the 1000 Genomes Project Phase 3 were investigated. ResultsForensic statistical results showed that the polymorphism information content values of the 43 deletion/insertion polymorphism loci in the two Tibetan groups exceeded 0.35. Moreover, the combined power of discrimination using the 43 deletion/insertion polymorphism loci was calculated to be 0.9999999999999999984 in the Qinghai Tibetan group and 0.9999999999999999921 in the Tibet Tibetan group. The cumulative power of exclusion using the 43 deletion/insertion polymorphism loci was calculated to be 0.999782512 in the Qinghai Tibetan group and 0.999886205 in the Tibet Tibetan group. Analysis of population genetics demonstrated that the two studied Tibetan groups shared close genetic relationships with East Asia populations. ConclusionThe set of 43 deletion/insertion polymorphism loci exhibited remarkable forensic efficacy, rendering it a promising tool for forensic practice. Population genetic analyses indicated that the two Tibetan groups had closer genetic affinities to East Asian populations.

Blood-Blister Aneurysms of the Internal Carotid Artery in Tibetan and Han Populations : A Retrospective Observational Study.

Blood-blister aneurysms (BBAs) of the internal carotid artery (ICA) are challenging lesions with high morbidity and mortality rates. Although research on BBAs is well documented in different populations, the study of BBAs in the Tibetan population is extremely rare. This study aimed to evaluate the characteristics of BBAs and analyze the treatment modalities and long-term outcomes in the Tibetan population in comparison with the Han population. The characteristics of patients with BBAs of the ICA from January 2009 to January 2021 at our institution were reviewed. The features of aneurysms, treatment modalities, complications, and follow-up outcomes were retrospectively analyzed. A total of 130 patients (41 Tibetan and 89 Han patients) with BBAs of the ICA who underwent treatment were enrolled. Compared with the Han group, the Tibetan group significantly demonstrated a high ratio of BBAs among ICAs (8.6%, 41/477 vs. 1.6%, 89/5563; p<0.05), a high ratio of vasospasm (34.1%, 14/41 vs. 6.7%, 6/89; p=0.001), a high risk of ischemic events (43.9%, 18/41 vs. 22.5%, 20/89; p<0.05), and a low ratio of good outcomes (modified Rankin scale, 0-2) at the 1-year follow-up (51.2%, 21/41 vs. 74.2%, 66/89; p<0.05). The multivariate regression model showed that ischemic events significantly contributed to the prediction of outcomes at 1 year. Further analysis revealed that microsurgery and vasospasm were associated with ischemic events. In comparison with Han patients, the Tibetan population had a high ratio of BBA occurrence, a high incidence of ischemic events, and a high ratio of poor outcomes. The endovascular approach showed more benefits in BBA patients.

Subject in motion: (de)capitalization and coping strategies of Tibetan "Sea Turtles" in China.

Previous studies on Chinese overseas students have generally presumed a smooth transition from mobility to mobility capital and have lacked an ethnic perspective. In this study, we adopt mobility capital as an analytical lens to explore the life trajectories of a group of Tibetans with studying abroad experiences. Drawing on qualitative data through multiple methods, we find a shift from collective-oriented expectations regarding studying abroad to individualist life planning and lifestyles after returning to work in the Tibet Autonomous Region (TAR). Before studying abroad, the informants viewed such experiences as important capital that could be later used to make a change for the Tibetan group, their local societies, and the state. Those views met a different reality after returning to TAR because the informants generally felt they were being viewed as potentially risk subjects in the workplace, which significantly impeded the capitalization of educational mobility at the institutional level. However, the informants developed coping strategies to find self-worth in private life by capitalizing on educational mobility. By addressing the subjective experiences of Tibetan informants in TAR and their associations with institutional contexts, this article not only engages an ethnicity-sensitive perspective to understand the politics of international educational mobility but also extends the discussion on individuals' experiences of educational mobility to the successional stage upon returning to their home societies. This article ultimately emphasizes the need for more culturally and politically reflexive policies that can sustain the flow of ethnic talents and help them realize their self-worth.

The transcriptomic and epigenetic alterations in type 2 diabetes mellitus patients of Chinese Tibetan and Han populations.

Due to the distinctive living environment, lifestyle, and diet, the Tibetan community in China has the lowest prevalence of T2DM and prediabetes among numerous ethnic groups, while Han community shows the highest statistic. In this study, we aim to conclude the clinical manifestations of both Tibetan and Han T2DM patients and their association with transcriptomic and epigenetic alterations. A cross-sectional study including 120 T2DM patients from Han and Tibetan ethnic groups were conducted between 2019 to 2021 at the Hospital of Chengdu University of Traditional Chinese Medicine. The various clinical features and laboratory tests were recorded and analyzed between the two groups. The genome-wide methylation pattern and RNA expression were determined by Reduced Representation Bisulfite Sequencing (RBBS) and Poly (A) RNA sequencing (RNA-seq) from leucocytes of peripheral blood samples in 6 Han and 6 Tibetan patients. GO analysis and KEGG analysis were conducted in differentially expressed genes and those with differentially methylated regions. Compared to Han, Tibetan T2DM individuals intake more coarse grains, meat and yak butter, but less refined grains, vegetables and fruit. They also showed increased BMI, Hb, HbA1c, LDL, ALT, GGT and eGFR, and decreased level of BUN. Among the 12 patients in the exploratory cohort, we identified 5178 hypomethylated and 4787 hypermethylated regions involving 1613 genes in the Tibetan group. RNA-seq showed a total of 947 differentially expressed genes (DEGs) between the two groups, with 523 up-regulated and 424 down-regulated in Tibetan patients. By integrating DNA methylation and RNA expression data, we identified 112 DEGs with differentially methylated regions (overlapping genes) and 14 DEGs with promoter-related DMRs. The functional enrichment analysis demonstrated that the overlapping genes were primarily involved in metabolic pathways, PI3K-Akt signaling pathway, MAPK signaling pathway, pathways in cancer and Rap1 signaling pathway. Our study demonstrates the clinical characteristics of T2DM differ subtly between various ethnic groups that may be related to epigenetic modifications, thus providing evidence and ideas for additional research on the genetic pattern of T2DM.

The clinical and pathological characteristics of IgA nephropathy patients in Tibet

BackgroundThere are few studies on immunoglobulin A nephropathy (IgAN) at high altitude. This study aimed to analyze the clinical and pathological characteristics of IgAN between Tibet and Beijing, which provided a basis for improving diagnosis and treatment in Tibet.MethodThe clinical and pathological data of 80 patients from the People’s Hospital of Tibet Autonomous Region (Tibetan group) and 991 patients from Peking University First Hospital (Beijing group) with IgAN proven by renal biopsy were compared retrospectively between January 2016 and July 2020. The kidney biopsy tissue was sent to the Department of Nephrology, Peking University First Hospital for pathological evaluation.ResultsThe proteinuria (2.9 [2.0, 4.9] vs. 1.1 [0.5, 2.4] g/day, P < 0.001) in the Tibetan group was significantly higher than that in the Beijing group. The serum albumin (30.4 ± 7.7 vs. 38.2 ± 5.5 g/L, P < 0.001) was significantly lower in the Tibetan group. The eGFR (77.7 ± 37.8 vs. 62.1 ± 33.6 ml/min/1.73 m2, P = 0.001) was higher in the Tibetan group. The percentage of patients with nephrotic syndrome in the Tibetan group was significantly higher than that in the Beijing group (33.8% vs. 4.7%, P < 0.001).ConclusionThere are differences in the clinical and pathological characteristics of IgAN between plateau and plain regions.

Forensic Efficiency Estimation of a Homemade Six-Color Fluorescence Multiplex Panel and In-Depth Anatomy of the Population Genetic Architecture in Two Tibetan Groups.

The genetic information of the Chinese Tibetan group has been a long-standing research hotspot among population geneticists and archaeologists. Herein, 309 unrelated individuals from two Tibetan groups living in Qinghai Province, China (CTQ), and Tibet Autonomous Region, China (CTT), were successfully genotyped using a new homemade six-color fluorescence multiplex panel, which contained 59 autosomal deletion/insertion polymorphisms (au-DIPs), two mini short tandem repeats (miniSTRs), two Y-chromosomal DIPs, and one Amelogenin. The cumulative probability of matching and combined power of exclusion values for this new panel in CTQ and CTT groups were 1.9253E-27 and 0.99999729, as well as 1.5061E-26 and 0.99999895, respectively. Subsequently, comprehensive population genetic analyses of Tibetan groups and reference populations were carried out based on the 59 au-DIPs. The multitudinous statistical analysis results supported that Tibetan groups have close genetic affinities with East Asian populations. These findings showed that this homemade system would be a powerful tool for forensic individual identification and paternity testing in Chinese Tibetan groups and give us an important insight for further perfecting the genetic landscape of Tibetan groups.

Oral Microbiota of Children Is Conserved across Han, Tibetan and Hui Groups and Is Correlated with Diet and Gut Microbiota.

The oral microbiota can be affected by several factors; however, little is known about the relationship between diet, ethnicity and commensal oral microbiota among school children living in close geographic proximity. In addition, the relationship between the oral and gut microbiota remains unclear. We collected saliva from 60 school children from the Tibetan, Han and Hui ethnicities for a 16S rRNA gene sequencing analysis and comparison with previously collected fecal samples. The study revealed that Bacteroidetes and Proteobacteria were the dominant phyla in the oral microbiota. The Shannon diversity was lowest in the Tibetan group. A PCA showed a substantial overlap in the distribution of the taxa, indicating a high degree of conservation among the oral microbiota across ethnic groups while the enrichment of a few specific taxa was observed across different ethnic groups. The consumption of seafood, poultry, sweets and vegetables was significantly correlated with multiple oral microbiotas. Furthermore, 123 oral genera were significantly associated with 191 gut genera. A principal coordinate analysis revealed that the oral microbiota clustered separately from the gut microbiota. This work extends the findings of previous studies comparing microbiota from human populations and provides a basis for the exploration of the interactions governing the tri-partite relationship between diet, oral microbiota and gut microbiota.

Genetic reconstruction and phylogenetic analysis by 193 Y-SNPs and 27 Y-STRs in a Chinese Yi ethnic group.

Yi is the seventh-largest ethnic group in China and features mountainous regional characteristics. The Liangshan Yi Autonomous Prefecture is the largest Yi agglomeration with isolated geographical conditions, profoundly impeding genetic communication. Here, we investigated 427 unrelated males of Liangshan from 193 Y-chromosome single nucleotide polymorphisms (Y-SNPs) and 27 Y-chromosome short tandem repeats (Y-STRs) to reveal the genetic structure and paternal phylogeny of the group. The haplogroup diversity reached 0.9169 with 46 different subhaplogroups by 193 Y-SNPs, and the haplotype diversity reached 0.9999 by 27 Y-STR loci. Multidimensional scaling (MDS), N-J tree, and Network were constructed to decipher and visualize the genetic relations between Yi and worldwide groups. Our results revealed: (1) the Network by Y-STRs and Y-SNPs showed the haplogroup D1a1a-M15 in the Liangshan Yi population was a ramification of Tibetan groups' expansion from west to east on the plateau; (2) the haplogroup distribution and the mismatch mutation analysis indicated the haplogroup O2a2b1a1a1a4a2-Z25929 of Liangshan Yi derived from manifold Southeast Asian immigrants; (3) a high-resolution Y-SNPs panel is vital to depict accurate paternal derivations and build an integrated and refining genetic structure of ethnic groups.

Investigation of control region sequences of mtDNA in Naqu Tibetan population from Northwestern China

Background The sequence polymorphisms of mitochondrial DNA (mtDNA) are valuable in forensic medicine and anthropological genetics. Aim We analysed the sequences of the mtDNA control region in 207 unrelated Tibetan individuals from the Naqu region, Tibet Autonomous Region in the People's Republic of China, and investigated the population structure of the region by population comparison with other groups. Subjects and methods Genomic DNA was extracted and hypervariable regions (HVS-I and HVS-II) were amplified and sequenced. Subsequently, sequences were aligned and compared with the revised Cambridge sequence. Moreover, population comparison was performed between the Naqu Tibetan group and the other groups. Conclusion Our study provided available data for exploring the mtDNA haplotype of the Tibetan population in the Naqu region, and population comparisons found that the Naqu Tibetan population has its own unique structure.

An epidemiological survey of mental disorders 5years after the Lushan earthquake in Ya'an, China.

This study aimed to (1) explore the prevalence and relevant influencing factors of different mental disorders 5years after the Lushan earthquake in Ya'an, China. An epidemiological mental health survey was conducted to identify the prevalence of mental disorders in general population in Ya'an. A multi-stage, group-matching random sampling method was adopted. Face-to-face interviews were done with a two-stage design by trained interviewers and psychiatrists. The 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) was used for the diagnosis. There were 8876 participants who were interviewed in this study. The total 12-month and lifetime prevalence of all mental disorders were 12.5% and 14.7%, respectively. There was a significant difference between males and females in the prevalence patterns of several mental disorders. Han ethnic group had higher prevalence of anxiety disorders (2.7%), and the Tibetan group had higher prevalence of alcohol-related disorders (5.0%). Logistic regression analysis showed that the areas severely affected by the earthquake had significantly higher prevalence of depressive disorders, and the extremely severe affected areas had significantly higher prevalence of trauma- and stressor-related disorders. Our findings show that the prevalence of a range of mental disorders 5years after the earthquake in Ya'an are high, and the prevalence of depressive and trauma- and stressor-related disorders may be influenced differently by the various severity of earthquake impact. This study may be crucial for the health policy-making, cultural-specific mental health services and long-term mental recovery after the earthquake.

A study of the construction times of the ancient cities in Ganjia Basin, Gansu Province, China

The Ganjia Basin in Xiahe County, Gansu Province, China, is located on the northeastern edge of the Tibetan Plateau. The area lies in the transitional zone between the Plateau ethnic groups dominated by ancestral Tibetans, and the Central Plains dynasties dominated by ancestral Han in history. The Ganjia Basin is therefore well suited to studying the history of the intermixing of the Han and Tibetan peoples. In this study, we collected samples of organic materials from two ancient cities, Bajiaocheng (BJC) and Sirougucheng (SRGC), in the Ganjia Basin, which were used for radiocarbon dating. Our aims were to determine the construction times and function of the cities, based on the radiocarbon ages, Bayesian age modeling, and the analysis of relevant historical records. The results are used to discuss the role of the Ganjia Basin in the conflicts between and the integration of the two ethnic groups during the historical period. We conclude that BJC was established during 663–732 CE (Common Era); its early occupation history can be divided into an initial establishment phase (670–780 CE) and a phase of regeneration (880–1030 CE). SRGC was probably built at the time of the transition between the Song and Yuan dynasties (∼1271 CE). Combining the dating results with an analysis of the architectural styles and historical records, we conclude that BJC was originally built by the Tubo Kingdom as a military stronghold, and its major functions were military, economic and religious, and to support the major eastward expansion of the Tubo. SRGC was most likely a temple-focused city intended to promote Tibetan Buddhism which was a major political and religious leadership for the Tibetans at that time, reflecting changes in the status of different religions in the Ganjia Basin. In addition, the intermixing and blending of the Han and Tibetan groups, reflected by the human activities in the Ganjia Basin, was an important demographic and cultural foundation for the formation of the culturally-diverse but spiritually-united modern Chinese people.

Population structure, genetic diversity, and selective signature of Chaka sheep revealed by whole genome sequencing

BackgroundChaka sheep, named after Chaka Salt Lake, are adapted to a harsh, highly saline environment. They are known for their high-grade meat quality and are a valuable genetic resource in China. Furthermore, the Chaka sheep breed has been designated a geographical symbol of agricultural products by the Chinese Ministry of Agriculture.ResultsThe genomes of 10 Chaka sheep were sequenced using next-generation sequencing, and compared to that of additional Chinese sheep breeds (Mongolian: Bayinbuluke and Tan; Tibetan: Oula sheep) to explore its population structure, genetic diversity and positive selection signatures. Principle component analysis and a neighbor-joining tree indicated that Chaka sheep significantly diverged from Bayinbuluke, Tan, and Oula sheep. Moreover, they were found to have descended from unique ancestors (K = 2 and K = 3) according to the structure analysis. The Chaka sheep genome demonstrated comparable genetic diversity from the other three breeds, as indicated by observed heterozygosity (Ho), expected heterozygosity (He), runs of homozygosity (ROH), linkage disequilibrium (LD) decay. The enrichment analysis revealed that in contrast to Mongolian or Tibetan lineage groups, the genes annotated by specific missense mutations of Chaka sheep were enriched with muscle structure development (GO:0061061) factors including insulin-like growth factor 1 (IGF1), growth differentiation factor 3 (GDF3), histone deacetylase 9 (HDAC9), transforming growth factor beta receptor 2 (TGFBR2), and calpain 3 (CAPN3), among others. A genome-wide scan using Fst and XP-CLR revealed a list of muscle-related genes, including neurofibromin 1 (NF1) and myomesin 1 (MYOM1), under potential selection in Chaka sheep compared with other breeds.ConclusionsThe comprehensive genome-wide characterization provided the fundamental footprints for breeding and management of the Chaka sheep and confirmed that they harbor unique genetic resources.

Insights into the genetic characteristics and population structures of Chinese two Tibetan groups using 35 insertion/deletion polymorphic loci.

Studying the genetic structure of each ethnic group is helpful to clarify the genetic background and trace back to the ethnic origin. Tibetan people have lived in the Qinghai-Tibet Plateau (mean elevation over 4500m) for generations, and have well adapted to thehigh-altitude environment. Due to the relatively closed geographical environment, Tibetans have preserved their representative physical characteristics and genetic information, thereby become an important research group in human genetics. In this study, genetic characteristics and population structures of two Tibetan groups (Qinghai Tibetans and Tibet Tibetans) were revealed by 35 insertion/deletion polymorphism (DIP) loci, aiming to provide valuable genetic information for population genetic differentiation analyses and forensic identifications. The combined discrimination power, cumulative exclusion probability and combined match probability of the 35 DIP loci in Qinghai Tibetan and Tibet Tibetan groups were 0.9999999999999945, 0.9988, 5.56623 × 10-15; and 0.9999999999999904, 0.9990, 9.69071 × 10-15, respectively, indicating that the panel possessed a strong capability for Tibetan personal identifications. Population differentiations and genetic relationship analyses among the two studied Tibetan groups and other 27 comparison populations were carried out using the Nei's DA genetic distances, population pairwise genetic distances F-statistics (FST), analysis of molecular variance (AMOVA), phylogenetic tree reconstruction, principal component analysis and STRUCTURE methods. Results demonstrated that the most intimate genetic relationships existed in these two Tibetan groups; and genetic similarities between two Tibetan groups and the populations from East Asia were much stronger than that between the Tibetan groups and other geographical populations. Furthermore, forensic ancestral informativeness assessments suggested that several loci could be regarded as ancestry informative markers inferring individual biogeographic origins as well as contributing to forensic anthropology and population genetic researches.

Population genetic data from 23 autosomal STR loci of Huaxia Platinum system in the Jining Han population.

BackgroundGenetic polymorphisms at 23 short tandem repeat (STR) loci were investigated in 1,215 Jining Han individuals from Jining city, Shandong province, eastern China.MethodsWe used population genetic data of 23 autosomal STR loci included in the Huaxia Platinum system to evaluate 1,215 unrelated Chinese Han individuals in the Jining Han population. Allele frequencies and forensic parameters of the STR loci were determined and genetic relationships among the Jining Han and other Chinese populations were evaluated.ResultsIn total, we observed 321 alleles, with frequencies ranging from 0.00041 to 0.52222. The combined discrimination power and probability of excluding paternity were 0.99999999999999999999999999919 and 0.99999999962, respectively. No deviations from HWE were observed at any loci. Population comparisons showed that the Xinjiang groups (Uyghur and Kazakh) and the Mongolian and Tibetan groups were isolated, while the Jining Han population clustered together with other populations, except the Guizhou Han population.ConclusionThis study demonstrated that 23 autosomal STR loci included in the Huaxia Platinum system are highly polymorphic and suitable for personal forensic identification and paternity testing in this population.

Ancestry informative DIP loci for dissecting genetic structure and ancestry proportions of Qinghai Tibetan and Tibet Tibetan groups.

Tibetans living in the Qing-Tibet plateau show unique genetic features since they are exposed to the high altitude environment. Accordingly, it is necessary for us to analyze genetic components of the Tibetan groups. Here, genetic structure and ancestry proportions of Tibet Tibetan and Qinghai Tibetan groups are dissected by using a previously published ancestral deletion/insertion polymorphisms (DIPs) panel. Genetic distributions of the analyzed DIPs in both Tibetan groups reveal that some DIPs show relatively balanced frequency distributions with the values ranging from 0.4 to 0.6, implying that these DIPs could be used as individual identification loci for forensic applications in both groups. Besides, the cumulative power of discrimination of the panel alsoreflects that the panel could serve as a valuable tool for forensic individual identifications in Tibet Tibetan and Qinghai Tibetan groups. Population genetic analyses including principal component analysis, DA genetic distances, phylogenetic tree, and genetic structure reveal that two studied Tibetan groups have closer genetic affiliations with East Asian populations. Genetic differentiation analyses of two Han populations, Xinjiang Uyghur and two Tibetan groups reveal that some DIP loci might be informative for differentiating Uyghurs from the other populations.

Revisiting the matrilineal lineages and hypoxic adaptation of highland Tibetans

The mitochondrial DNA (mtDNA) plays a vital role in forensic, anthropological, biogeographical and genealogical studies. In the present study, we sequenced 59 mitochondrial genomes of Tibetan individuals settling in Muli Tibetan Autonomous County of Sichuan Province using the Precision ID mtDNA Whole Genome Panel and Ion S5 XL system. Meanwhile, 192 published complete mitogenomes from five Tibetan populations were included for further analysis. All 251 investigated Tibetan participants were assigned to 98 unique subclades pertained to the macrohaplogroups M and N, and 17 subhaplogroups were considered as major haplogroups of Tibetans since these subhaplogroups accounted for considerably high frequencies in randomly selected Tibetans. It was noteworthy that M9a1a1c1b1a was the predominant subhaplogroup in the Tibetans collectively. Furthermore, the nonsynonymous substitutions and synonymous substitutions ratios (N/S) of Tibetans, Tibetan highlanders (Monpas, Lhobas, Dengs and Sherpas), non-Tibetan highlanders and general populations were estimated to evaluate the potential selective constraints. The N/S ratio in the Tibetan groups (0.503) is higher than that in Tibetan highlanders (0.465), non-Tibetan highlanders (0.430) and general populations (0.415). The distributions of N/S ratio in 13 protein-coding genes revealed that significant differences were existed in COX2, ATP8 genes, which likely contributed to hypoxic adaptation.

Comparison of risk factors and short-term and long-term prognosis of pulmonary embolism between the Tibetan and Han people

Objective: To compare the differences of risk factors and prognosis of pulmonary embolism (PE) between the Tibetans and the Hans. Methods: Patients over 18 years old with confirmed PE and complete clinical data from West China Hospital of Sichuan University from January 2010 to January 2016 were prospectively enrolled and divided into Tibetan group and Han group. Clinical data were collected to compare risk factors and short-term prognosis between Han group and Tibetan group. In addition, a 2-year follow-up was conducted among patients after discharge to investigate the long-term prognosis. Results: A total of 90 patients in Tibetan group and 626 patients in Han group were finally included in this study. Patients in Tibetan group were younger than Han group [(52.2±15.8) vs (59.8±16.6) years old, P<0.001], and the proportion of elderly patients (age ≥70 years) in Tibetan group was significantly lower than that of Han group (15.6% vs 33.7%, P=0.001). The hemoglobin, hematocrit, platelet counts and fibrinogen in Tibetan group were higher than those in Han group [(134.0±32.0) vs (122.2±25.7) g/L, (41.2±9.2)% vs (37.6±7.3)% and (222.2±97.5)×10(9)/L vs (187.5±87.2)×10(9)/L, 3.71(2.51, 4.89) vs 3.31(2.44, 4.42) g/L; P<0.001, <0.001 and P=0.001, 0.048, respectively]. Malignancy and chronic obstructive pulmonary disease were more common in Han group (P=0.011, 0.001), while prior venous thromboembolism history, pregnancy or a history delivery within 1 month were more common in Tibetan group (P=0.041, 0.001). Both short-term and long-term mortality in Tibetan group were significantly lower than that in Han group (2.2% vs 11.5%, 13.6% vs 24.9%; P=0.005, 0.020). Conclusions: Hypercoagulable state plays an important role in the pathogenesis of PE in Tibetan patients. Both short-term and long-term prognosis of PE in Tibetan patients are better than that in Han patients.