Whole Mitochondrial DNA Sequencing Analysis in 47 Han Populations in Southwest China

Analysis of maternal genetic structure of mitochondrial DNA control region from Tai-Kadai-speaking Buyei population in southwestern China

BACKGROUND

Even though the Buyei are a recognised ethnic group in southwestern China, there hasn't been much work done on forensic population genetics, notably using mitochondrial DNA. The sequences and haplogroups of mitochondrial DNA control regions of the Buyei peoples were studied to provide support for the establishment of a reference database for forensic DNA analysis in East Asia.

METHODS AND RESULTS

The mitochondrial DNA control region sequences of 200 Buyei individuals in Guizhou were investigated. The haplotype frequencies and haplogroup distribution of the Buyei nationality in Guizhou were calculated. At the same time, the paired Fst values of the study population and other populations around the world were computed, to explore their genetic polymorphism and population relationship. A total of 179 haplotypes were detected in the Buyei population, with frequencies of 0.005-0.015. All haplotypes were assigned to 89 different haplogroups. The haplotype diversity and random matching probability were 0.999283 and 0.0063, respectively. The paired Fst genetic distances and correlation p-values among the 54 populations revealed that the Guizhou Buyei was most closely related to the Henan Han and the Guizhou Miao, and closer to the Hazara population in Pakistan and the Chiang Mai population.

CONCLUSIONS

The study of mitochondrial DNA based on the maternal genetic structure of the Buyei nationality in Guizhou will benefit the establishment of an East Asian forensic DNA reference database and provide a reference for anthropological research in the future.

The mitochondrial DNA HVI and HVII sequences and haplogroup distribution in a population sample from Vietnam

BACKGROUND

Mitochondrial DNA (mtDNA) analysis has been used in forensics and requires well-established population databases for statistical interpretations. However, high-quality mtDNA data from Vietnamese population samples have been limited.

AIM

To examine the mtDNA sequences and haplogroup compositions of a Vietnamese population to provide an mtDNA dataset that can further be used to construct a Vietnamese-specific reference database.

SUBJECTS AND METHODS

A total of 173 Vietnamese individuals were analysed for two hypervariable regions (HVI and HVII) of mtDNA. Forensic parameters were calculated and haplogroup assignment was performed based on the resulting mtDNA haplotypes. Genetic relationships between the Vietnamese and other Asian populations were investigated through principal component analysis (PCA) and pairwise F_st.

RESULTS

The Vietnamese population sample consisted of 145 different haplotypes with a random match probability of 0.96%, a power of discrimination of 0.9904, and a haplotype diversity of 0.9962. The samples were assigned to 83 haplogroups that were commonly reported in Asia. PCA and pairwise F_st revealed close relationships of the Vietnamese population with other Asian populations, especially with populations in proximity.

CONCLUSION

The results from this study can contribute to the current genetic information content as a supplementary mtDNA reference dataset for forensic investigations and phylogenetic research.

Genetic analysis of the mitochondrial DNA control region in Tai-Kadai-speaking Dong population in southwest China

BACKGROUND

Dong people in Southwest China are officially recognised as an ethnic group, but there has been a lack of population genetic research on this group, especially based on mitochondrial DNA data.

AIM

To study the sequences and haplogroups of the mitochondrial DNA control region in a typical Dong population, and to provide help for the construction of a forensic mitochondrial DNA analysis reference database in East Asia.

SUBJECTS AND METHODS

The sequences of the mitochondrial DNA control region were analysed in 200 individuals of Dong in Guizhou. The haplotype frequencies, haplogroup distribution and paired Fst values of Guizhou Dong and 51 other populations in the world were calculated and explained to explore the genetic polymorphism and population relationships.

RESULTS

A total of 180 haplotypes were detected, with frequencies of 0.005-0.02. All haplotypes were assigned to 97 different haplogroups. The haplotype diversity and random matching probability were 0.998643 and 0.00635, respectively. The paired Fst values and correlation p values of 52 populations showed that the Guizhou Dong had the closest genetic relationship with the Henan Han and the Guizhou Miao in China, and were closest to the Punjab population in Pakistan and the Kashmiri population when compared with the world populations.

CONCLUSIONS

Our study was based on the matrilineal genetic structure of Guizhou Dong to study mitochondrial DNA, which was helpful to promote the establishment of the forensic DNA reference database in East Asia and provide reference for anthropological research.

ALDH2 gene rs671 G > a polymorphism and the risk of colorectal cancer: A hospital-based study

BACKGROUND

The susceptibility to some cancers is linked to genetic factors, such as aldehyde dehydrogenase 2 (ALDH2) polymorphisms. The relationship between ALDH2 rs671 and colorectal cancer (CRC) is not clear in Hakka population.

METHODS

Between October 2015 and December 2020, a total of 178 CRC patients and 261 controls were recruited. ALDH2 rs671 was genotyped in these subjects, medical records (smoking history, drinking history and blood cell parameters) were collected, and the relationship between these information and CRC was analyzed.

RESULTS

The proportion of the ALDH2 rs671 G/G, G/A, and A/A genotype was 48.3%, 44.4%, and 7.3% in patients; 62.1%, 34.1%, and 3.8% in controls, respectively. The difference of ALDH2 genotypes distribution between cases and controls was statistically significant (p = 0.011). The higher percentage of smokers and alcoholics, higher level of neutrophil to lymphocyte ratio (NLR), platelet count, and platelet to lymphocyte ratio (PLR), and lower level of lymphocyte count, lymphocyte to monocyte ratio (LMR), and mean hemoglobin concentration were observed in patients. Logistic regression analysis indicated that ALDH2 rs671 G/A genotype (G/A vs. G/G) (adjusted OR 1.801, 95% CI 1.160-2.794, p = 0.009) and A/A genotype (A/A vs. G/G) (adjusted OR 2.630, 95% CI 1.041-6.645, p = 0.041) in the co-dominant model, while G/A + A/A genotypes (G/A + A/A vs. G/G) (adjusted OR 1.883, 95% CI 1.230-2.881, p = 0.004) in the dominant model were risk factors for CRC.

CONCLUSIONS

Individuals carrying ALDH2 rs671 A allele (G/A, A/A genotypes) may be at increased risk of colorectal cancer.

The mitochondrial DNA control region sequences from the Chinese Sui population of southwestern China

BACKGROUND

Sui people are officially recognised people living in southwest China, but there has been a lack of genetic research, especially based on mitochondrial DNA data.

AIM

To study the sequences and haplogroups of the mitochondrial DNA control region in a typical Sui population, with the aim of helping to promote the establishment of a forensic DNA analysis reference database in East Asia.

SUBJECTS AND METHODS

We analysed 201 Sui individuals and observed the sequences of the mitochondrial DNA control region. We calculated and explained the haplotype frequencies, haplogroup distribution and pairwise Fst values between the Sui and 47 other populations in the world, in order to explore genetic polymorphisms and population relationships.

RESULTS

161 haplotypes were found in the Sui population, with frequencies of 0.0049-0.0199. All samples were assigned to 80 different haplogroups. The haplotype diversity and random matching probability were 0.999938 and 0.024729, respectively. The pairwise Fst values and correlation p-values of 48 populations showed that the Sui population was most closely related to the Miao population in Guizhou and the Han population in Henan, and closer to the Punjab population and Pukhtunkhwa population in Pakistan, and was significantly different from the other 43 groups. Compared with the other 43 groups, it is relatively isolated.

CONCLUSION

Our results show that the study of mitochondrial DNA based on the analysis of matrilineal genetic structure of the Sui population can help to promote the establishment of a forensic DNA reference database in East Asia and provide reference for future anthropological research.

[The role of mitochondria in pathological mechanisms of innate immunity in multiple]

The review discusses the role of mitochondria in multiple sclerosis (MS). Previously, damage to the mitochondria was regarded as a manifestation of secondary damage to axons and neurons, i.e. as a marker of neurodenegation. Recently, the role of mitochondria in the early stages of MS development, when they could participate in the activation of innate immunity and trigger activation of autoimmune responses of acquired immunity, has been increasingly discussed. The role of polymorphism mitochondrial DNA changes in MS is discussed.

Mitochondrial genome and risk of multiple sclerosis

Mitochondrial DNA (mtDNA) polymorphism makes a certain contribution to the formation of a genetic risk of multiple sclerosis (MS).

Objective: to analyze the frequency of mtDNA variants in patients with MS and control individuals in the Russian population. A similar study was conducted for the first time.

Patients and methods. The polymorphism of mtDNA was studied in the Russian population: in 283 unrelated patients with relapsing-remitting MS and in 290 unrelated healthy controls matched for gender and age.

Results and discussion. The frequency of haplogroup J in the patients with MS was twice higher than that in the control group (p=0.0055) (odds ratio (OR) 2.00; 95% confidence interval (CI). 1.21–3.41). This association was mostly observed in women (p=0.0083) (OR 2.20; 95% CI, 1.19–4.03). There was also a significant association of the A allele of MT-ND5 (m. 13708G>A) with MS (p=0.03) (OR 1.89; 95% CI 1.11–3.32). Sex stratification showed that the association with MS was significant only in women (p=0.009; OR, 2.52; 95% CI, 1.29–5.14). Further investigations will aim to analyze mtDNA variability (at the level of individual polymorphisms, haplogroups, and whole genome) in patients with relapsing-remitting MS and in those with primary progressive MS versus healthy individuals and patients with relapsing-remitting MS according to disease severity.

Conclusion. The data obtained in the Russian population suggest that mtDNA variations are involved in MS risk, to a greater extent in women.