Novel mutations found in mitochondrial diabetes in Chinese Han population

Screening of mitochondrial mutations in Saudi women diagnosed with gestational diabetes mellitus: A non-replicative case-control study

Introduction

Among metabolic disorders, gestational diabetes mellitus (GDM) is specified as hyperglycemia caused by glucose or carbohydrate intolerance defects. GDM is distinguished by oxidative stress, and has been connected to mitochondrial dysfunction. Previous studies have documented the relation between A12026G, A8344G and A3243G mutations in ND4, tRNA^Leu(UUR), and tRNA^Lys genes in different modes of diabetes.

Aim

The purpose of this study was to investigate into the relationship between GDM women and common mitochondrial mutations including A12026, A8344G, and A3243G in Saudi women.

Methods

In this case-control study, we have opted 96 GDM and 102 non-GDM pregnant women and DNA was extracted using EDTA blood and based on specific primers, Polymerase Chain Reaction was followed and then Restriction Fragment Length Polymorphism (RFLP) analysis was performed. Restriction enzymes was cross-checked with Lambda DNA and 10% of the purified PCR products were performed the Sanger sequencing analysis to reconfirm the RFLP analysis of the studied results.

Results

None of the heterozygous and homozygous mutations were not observed in our study. All the subjects were turned to be homozygous normal genotypes.

Conclusion

This study confirms that A12026, A8344G, and A3243G mutations have no role in the Saudi women with GDM.

Mutational Analysis of Mitochondrial tRNA Genes in 200 Patients with Type 2 Diabetes Mellitus

Objective

Previous studies showed that variants in mitochondrial DNA (mtDNA) are associated with type 2 diabetes mellitus (T2DM). However, the relationships between mitochondrial tRNA (mt-tRNA) variants and T2DM remain poorly understood.

Methods

In this study, we performed a mutational screening of 22 mt-tRNA genes in a cohort of 200 Han Chinese subjects with T2DM and 200 control subjects through PCR–Sanger sequencing. The identified mt-tRNA variants were assessed for their pathogenicity via the phylogenetic approach, structural and functional analysis. Furthermore, two Han Chinese pedigrees with maternally inherited diabetes and deafness (MIDD) were reported by clinical and genetic assessments.

Results

A total of 49 genetic variants in mt-tRNA genes were identified; among them, 31 variants (17 pathogenic/likely pathogenic) were absent in controls, located at extremely conserved nucleotides, may have potential structural and functional significance, thereby considered to be T2DM-associated variants. In addition, sequence analysis of entire mitochondrial genomes of the matrilineal relatives from two MIDD pedigrees revealed the occurrence of tRNA^Leu(UUR) A3243G and T3290C mutations, as well as sets of polymorphisms belonging to mitochondrial haplogroups F2 and D4. However, the lack of any functional variants in connexin 26 gene (GJB2) and tRNA 5-methylaminomethyl-2-thiouridylate (TRMU) suggested that nuclear genes may not play active roles in clinical expression of MIDD in these pedigrees.

Conclusion

Our data indicated that mt-tRNA variants were associated with T2DM, screening for mt-tRNA pathogenic mutations was recommended for early detection and prevention of mitochondrial diabetes.

Investigation of the mtDNA mutations in Syrian families with non-syndromic sensorineural hearing loss

OBJECTIVE

Hearing loss is a common sensory disorder, and at least 50% of cases are due to a genetic etiology. Several mitochondrial DNA mutations (mtDNA) have been reported to be associated with nonsyndromic hearing loss (NSHL) in different population. However, There is no previous available data about the frequency of mtDNA mutations as etiology for deafness in Syrian. The aim of present study is to investigate the incidence of common mt DNA mutations in our families with congenital hearing loss and not related to the ototoxicity or aminoglycosides.

METHODS

A total of 50 deaf families were enrolled in the present study. Direct sequencing and PCR-RFLP methods were employed to detect seven mt DNA mutations, including A1555G, A3243G, C1494T, G3316A, T7510C, A7445G, and 7472insC.

RESULTS

Our results revealed a high prevalence of mt DNA mutation (10%) in deaf families (5/50). In surprising, the unexpected mutations were observed. The G3316A mutation was found in 2 families as homoplasmic genotype. Also, we found the homoplasmic and heteroplasmic genotype for the C1494T mutation in two families. In one family the heteroplasmic genotype for T7510C mutation was observed; this family harbor 35delG mutation in GJB2 gene. None of the common mtDNA mutations (A1555G, A3243G) and other mutations (A7445G, 7472insC) were detected here.

CONCLUSION

Our findings indicate to significant contribution of the mt DNA mutations in our families with NSHL. The presented data is the first report about mt DNA and it will improve the genetic counseling of hearing impaired in Syrian families.

Interaction between endothelial nitric oxide synthase rs1799983, cholesteryl ester-transfer protein rs708272 and angiopoietin-like protein 8 rs2278426 gene variants highly elevates the risk of type 2 diabetes mellitus and cardiovascular disease

Background

The aim of the present study was to examine the association of angiopoietin-like proteins-8 (ANGPTL8) rs2278426, cholesteryl ester-transfer protein (CETP) rs708272 and endothelial nitric oxide synthase (NOS3) rs1799983 variants with type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD), and to investigate the effect of the potential interaction between these variants on disease risk.

Methods

Our study included 272 subjects classified into 68 patients with T2DM, 68 patients with T2DM complicated with CVD and 136 control subjects. ANGPTL8 c194C>T, CETP Taq1B and NOS3 G894T polymorphisms were genotyped using TaqMan^® SNP Genotyping Assay.

Results

The presence of NOS3, ANGPTL8, and homozygous CETP B1 variants were associated with increased risk of T2DM by 3.07-, 2.33- and 1.75-fold, respectively. NOS3 variant was associated with 3.08-fold increased risk of CVD (95% CI 1.70–5.60), while ANGPTL8 C allele was associated with 2.8-fold increased risk of CVD in T2DM patients (95% CI 1.13–6.97). Concomitant presence of both, CETP B1 and NOS3 T allele, associated with increased risk of T2DM, CVD and CVD in T2DM by 8.36-, 6.33- and 7.87-fold, respectively, while concomitant presence of ANGPTL8 variant with either CETP B1 or NOS3 T allele was not associated with increased risk of T2DM or CVD. However, concomitant presence of the three variants together elevated the risk of T2DM by 13.22-fold (p = 0.004), CVD risk by 8.86-fold (p = 0.03) and highly elevated the risk of CVD in T2DM patients by 13.8-fold (p = 0.008).

Conclusions

Concomitant presence of CETP B1, NOS3 T and ANGPTL8 T alleles augments the risk of CVD and T2DM. Further studies to clarify the mechanism of gene–gene interaction in the pathogenesis of CVD and T2DM are needed.

The clinical characteristics of patients with mitochondrial tRNA Leu(UUR)m.3243A > G mutation: Compared with type 1 diabetes and early onset type 2 diabetes

OBJECTIVE

This study presents nine patients with mitochondrial tRNA Leu (UUR) m.3243A>G mutation and compares the clinical characteristics and diabetes complications with type 1 diabetes (T1DM) or early onset type 2 diabetes (T2DM).

METHODS

The study covers 9 patients with MIDD, 33 patients with T1DM and 86 patients (age of onset ≤35years) with early onset T2DM, matched for sex, age at onset of diabetes, duration of diabetes. All patients with MIDD were confirmed as carrying the m.3243A>G mitochondrial DNA mutation. Serum HbA1c, beta-cell function, retinal and renal complications of diabetes, bone metabolic markers, lumbar spine and femoral neck BMD bone mineral density were compared to characterize the clinical features of all patients.

RESULTS

Nine patients were from five unrelated families, and the mean (SD) onset age of those patients was 31.2±7.2year. Two patients required insulin at presentation, and six patients progressed to insulin requirement after a mean of 7.2years. β-Cell function in the MIDD group was intermediate between T1DM and early-onset T2DM. In MIDD, four patients were diagnosed as diabetic retinopathy (4/9) and five patients (5/9) had macroalbuminuria. The number of patients with diabetic retinopathy and macroalbuminuria in the MIDD group was comparable to T1DM or early-onset T2DM. The rate of osteoporosis (BMD T-score<-2.5 SD) in the patient with MIDD was higher than the T1DM or early-onset T2DM group.

CONCLUSION

Our study indicates that of the nine subjects with MIDD, three patients (1-II-1, 1-II-3, 1-II-4) who came from the same family had a history of acute pancreatitis. Compared with T1DM or early-onset T2DM matched for sex, age, duration of diabetes, MIDD patients had the highest rate of osteoporosis.

Mitochondrial haplogroup M9a1a1c1b is associated with hypoxic adaptation in the Tibetans

While hypoxic environment at high altitude remains a major challenge for travelers from low-altitude areas, Tibetans have adapted to the high-altitude environment. Mitochondria are the energy conversion and supplement centers in eukaryotic cells. In recent years, studies have found that the diversity of the mitochondrial genome may have a role in the adaptation to hypoxia in Tibetans. In this study, mitochondrial haplogroup classification and variant genotyping were performed in Tibetan and Han Chinese populations living at different altitudes. The frequencies of mitochondrial haplogroups B and M7 in the high-altitude population were significantly lower compared with those in the low-altitude population (P=0.003 and 0.029, respectively), whereas the frequencies of haplogroups G and M9a1a1c1b in the high-altitude group were significantly higher compared with those in the low-altitude group (P=0.01 and 0.002, respectively). The frequencies of T3394C and G7697A, which are the definition sites of haplogroup M9a1a1c1b, were significantly higher in the high-altitude group compared with that in the low-altitude group (P=0.012 and 0.02, respectively). Our results suggest that mitochondrial haplogroups B and M7 are associated with inadaptability to hypoxic environments, whereas haplogroups G and M9a1a1c1b may be associated with hypoxic adaptation. In particular, the T3394C and G7697A variants on haplogroup M9a1a1c1b may be the primary cause of adaptation to hypoxia.

Mitochondrial complex I and V gene polymorphisms in type II diabetes mellitus among high risk Mizo-Mongoloid population, Northeast India

Introduction

The study was carried out to identify the polymorphisms in mitochondrial genes (ATPase and ND1) in type 2 Diabetes Mellitus (T2DM) from Mizo population and to correlate the involvement of demographic factors.

Findings

In the present study, 58 patients and 50 healthy volunteers were considered. The mutations observed were mostly base substitutions and were similar as reported for other populations. Three mutations are unreported and were found to be novel polymorphisms for diabetic disease. One heteroplasmic variation (MT3970 C > T) was found in 36.36 % of samples. Subjects with excessive smoked meat consumption and customary habit of smoking (ORs: 4.92; 95 % CI: 0.96–25.21) were found to be more prone to T2DM. Mitochondrial genes sequence analysis revealed the genetic variability between the healthy and diabetic samples.

Conclusion

Mitochondrial ATPase and ND1 gene polymorphisms may be involved in triggering the risk for T2DM.

Electronic supplementary material

The online version of this article (doi:10.1186/s41021-016-0034-z) contains supplementary material, which is available to authorized users.

Association study of mitochondrial DNA polymorphisms with type 2 diabetes in Tunisian population

Mitochondrial DNA (mtDNA) variation may play an important role in the pathogenesis of type 2 diabetes (T2Ds). In this study, we aimed to explore whether mtDNA variants contribute to the susceptibility to T2Ds in a Tunisian population. The hypervariable region 1 (HVS1) of the mtDNA of 64 T2Ds patients and 77 healthy controls was amplified and sequenced. Statistical analysis was performed using the STATA program. Analysis of the total screened variants (N = 88) from the HVS1 region showed no significant difference in the distribution of all polymorphisms between T2Ds and controls, except for the variant G16390A which was more frequent in T2Ds (15.9%) than in controls (5.4%) (p = 0.04). The association of G16390A was not detected after multivariate regression analysis. Similarly, analysis of the distribution of mitochondrial haplogroups within our dataset showed 18 distinct major haplogroups with no significant difference between T2Ds and controls. Except, the weakly association found for the G16390A variant, our results showed that none of the tested polymorphisms from the HVS1 region have a major role in T2Ds pathogenesis in the studied Tunisian population even when taking into account the population stratification.

Mitochondrial DNA mutations in diabetes mellitus patients in Chinese Han population

BACKGROUND AND OBJECTIVE

Mutations of mitochondrial DNA are associated with diabetes mellitus (DM). The present case-control study aimed to investigate the mutations of mitochondrial DNA in DM patients of Chinese Han ethnicity.

METHODS AND RESULTS

A total of 770 DM patients and 309 healthy control individuals were enrolled. The mitochondrial DNA was extracted from blood cells and analyzed by the polymerase chain reaction-restriction fragment length polymorphism assay. In the diabetes group, there were 13 (1.69%) individuals carrying the mt3243 A → G mutation while none of the healthy control had this mutation. Though the 14709, 3316, 3394, and 12026 mutation variants were identified in 9, 17, 18 and 28 in DM patients respectively, there were no significant differences compared with control group. And the 3256, 8296, 8344, 8363, 3426 and 12258 mutations were not detected in either group. In the diabetes group, two double mutations were identified: A3243G+T3394C and A3243G+A12026G.

CONCLUSION

Our data suggested that mitochondrial gene tRNA(Leu(UUR)) 3243 A → G mutation may be one risk of prevalence of DM and associated with worse clinical status in Chinese Han population.

The mitochondrial DNA Northeast Asia CZD haplogroup is associated with good disease-free survival among male oral squamous cell carcinoma patients

Reprogramming of energy metabolism in cancer cells has been directly/indirectly linked to mitochondria and mitochondrial functional defects and these changes seem to contribute to the development and progression of cancer. Studies have indicated that mitochondrial DNA haplogroups are associated with risk in relation to various diseases including cancer. However, few studies have examined the effect of haplogroups on cancer prognosis outcome. In order to explore the role of haplogroups on oral squamous cell carcinoma (OSCC) prognosis, the mitochondrial genomes of 300 male OSCC patients were comprehensively analyzed by direct sequencing. They were then haplotyped and grouped into four major geographic haplogroups, namely the East Asia AN, Southeast Asia RBF, East Asia MGE and Northeast Asia CZD groups. The Kaplan-Meier plot analysis indicated that individuals who were members of the CZD haplogroup showed a significant association with better disease-free survival (DFS) than the other three haplogroups and this phenomenon still existed after adjusting for tumor stage, differentiation and age at diagnosis (hazard ratio=0.55; 95% CI=0.36-0.84). In addition, an interaction between membership of the RBF haplogroup and radiotherapy/chemo-radiotherapy in DFS was also identified. The results strongly support the hypothesis that an individual's haplogroup, by defining their genomic background, plays an important role in tumor behavior and mitochondrially-targeted anticancer drugs are promising future therapeutic approaches.

Strong interaction between T allele of endothelial nitric oxide synthase with B1 allele of cholesteryl ester transfer protein TaqIB highly elevates the risk of coronary artery disease and type 2 diabetes mellitus

BACKGROUND

The present study was conducted to investigate the possible outcome of interaction between endothelial nitric oxide (NOS3) G894T and cholesteryl ester transfer TaqIB variants on the risk of coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM). The sample included a total of 207 CAD patients (102 CAD patients with T2DM and 105 CAD patients without T2DM). There were also 101 patients with T2DM and 92 age- and sex-matched healthy individuals as controls. All study participants were from Western Iran. The sample was genotyped by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

The presence of NOS3 T allele was not associated with the risk of CAD or T2DM, and the CETP B1 allele was only significantly associated with the increased risk of CAD in total CAD patients (odds ratio (OR) = 5.1, p = 0.019). However, the concomitant presence of both CETP B1 and NOS3 T alleles significantly increased the risk of CAD in total CAD patients (OR = 18.1, p < 0.001), in CAD patients without T2DM (OR = 27.1, p = 0.03), and in CAD patients with T2DM (OR = 13.5, p = 0.002). Also, the presence of both alleles increased the risk of T2DM (OR = 12, p = 0.004).

CONCLUSIONS

Our findings, for the first time, indicate that NOS3 T allele strongly interacts with CETP B1 allele to augment the risk of CAD and T2DM in the population of Western Iran.

Large-scale screening of mitochondrial DNA mutations among Iranian patients with prelingual nonsyndromic hearing impairment

Hereditary hearing impairment (HI) is a genetically heterogeneous disorder caused by mutations either in nuclear DNA (nDNA) or in mitochondrial DNA (mtDNA). The nDNA mutations account for the majority of prelingual nonsyndromic HI (NSHI). The present survey was conducted to screen for known pathogenic mtDNA mutations including A1555G, A3243G, C1494T, and A7445G to provide an accurate estimate of their prevalence in prelingual NSHI for the first time in the Iranian subpopulations. One thousand unrelated probands with NSHI (including both GJB2-negative and GJB2 heterozygote cases) and 1000 healthy matched controls were investigated using the PCR/RFLP method followed by DNA sequencing to confirm the observed mtDNA mutations. Two of the studied mutations, namely A3243G and A7445G, were each found in a single family (a frequency of 0.1% for each). Mutation screening for A3243G followed by DNA sequencing led to the identification of G3316A substitution, with no prior link to HI. Surprisingly, screening for A3243G in the studied population identified 6 cases (0.6%) in probands and 10 (1%) in normal subjects. A1555G, the most common mtDNA mutation associated with deafness in other populations, was not found in the studied samples. To conclude, our findings indicate G3316A as a nonpathogenic variant in the prelingual NSHI subpopulations of Iran and suggest that mtDNA mutations do not play a major role in the etiology of NSHI in Iran.

Association between cholesteryl ester transfer protein TaqIB variants and risk of coronary artery disease and diabetes mellitus in the population of western Iran

AIMS

To shed light on the previously inconsistent results about the association of cholesteryl ester transfer protein TaqIB (CETP TaqIB) variants, high-density lipoprotein cholesterol (HDL-C) levels, and the risk of coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM).

METHODS

To determine the frequency of CETP TaqIB variants and to examine the possible association between CETP TaqIB polymorphism with CAD and T2DM, we studied 207 unrelated patients with CAD, 101 patients with T2DM, and 92 controls. The CETP TaqIB variants were detected by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Logistic regression analysis indicated that the B1 allele of CETP was significantly associated with increased risk of CAD (odds ratio, OR 1.65 [95% confidence interval, CI 1.2-2.3, p=0.005]) and T2DM (OR 1.7 [95% CI 1.13-2.54, p=0.005]). Adjusted logistic regression analysis for the effects of age, sex, hypertension, diabetes, and hyperlipidemia was performed; and a significant association was found between the B1 allele and risk of CAD (OR 1.9 [95% CI 1-3.6, p=0.049]) in patients with CAD. There were no associations between the CETP alleles and the levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol, and HDL-C in studied groups.

CONCLUSIONS

The results of the present study revealed that the CETP B1 allele is associated with increased risk of CAD and T2DM independent of plasma HDL-C level in our population.

MtDNA haplogroups M7 and B in southwestern Han Chinese at risk for acute mountain sickness

We conducted a case-control study to investigate the association of mitochondrial DNA (mtDNA) haplogroups with acute mountain sickness (AMS) in Han Chinese from southwestern (SW) China. Pearson's chi-square test or Fisher's exact test revealed significant reduction of mtDNA haplogroups D and M9, while a significant increase of haplogroup M7 in AMS subjects compared with non-AMS subjects. The multivariate logistic regression analysis after adjustment for body mass index (BMI), a risk factor of AMS in the present study, showed that both D and M9 were associated with significantly decreased risk of AMS, while M7 was associated with a significantly increased risk of AMS (OR=0.605, p=0.000; OR=0.037, p=0.001, and OR=2.419, p=0.001, respectively). In addition, further analysis stratified by the AMS severities indicated that haplogroup B was correlated with a 2.41-folds increased risk of developing severe AMS (95%C.I=1.288-4.514, p=0.006). Our findings provide evidence that, in SW Han Chinese, mtDNA haplogroups D and M9 are related to individual tolerance to AMS, while haplogroups M7 and B are risk factors for AMS.

Mitochondrial and nuclear gene mutations in the type 2 diabetes patients of Coimbatore population

Involvement of mitochondrial and nuclear gene mutations in the development of type 2 diabetes (T2D) has been established well in various populations around the world. Previously, we have found the mitochondrial A>G transition at nucleotide position 3243 and 8296 in the T2D patients of Coimbatore population. This study is aimed to screen for the presence of various mitochondrial and nuclear DNA mutations in the T2D patients of Coimbatore to identify most prevalent mutation. This helps in identifying the susceptible individuals based on their clinical phenotype in future. Blood samples were collected from 150 unrelated late-onset T2D patients and 100 age-matched unrelated control samples according to World Health Organization criteria. Genotyping for the selected genes was done by polymerase chain reaction-single strand confirmation polymorphism, direct sequencing, and polymerase chain reaction-restriction fragment length polymorphism. The mitochondrial T>C transition at 8356 and nuclear-encoded GLUT1 gene mutation were found in the selected T2D patients. The T8356C mutation was found in two patients (1.3%), and the clinical characteristics were found to be similar in both the patients whereas GLUT1 gene mutation was found in seven patients. Four out of seven patients showed homozygous (-) genotype and three patients showed heterozygous (±) genotype for the mutant allele XbaI. Among these three patients, one patient was found to have elevated level of urea and creatinine with the history of kidney dysfunction and chronic T2D. Our results suggest that the T8356C and GLUT1 gene mutations may have an important role in developing late-onset T2D in Coimbatore population. Particularly, individuals with GLUT1 gene may develop kidney dysfunction at their later age.

The heteroplasmic m.14709T>C mutation in the tRNA(Glu) gene in two Tunisian families with mitochondrial diabetes

Diabetes mellitus (DM) is a heterogeneous disorder characterized by the presence of chronic hyperglycemia. Genetic factors play an important role in the development of this disorder, and several studies reported mutations in nuclear genes implicated in the insulin function. Besides, DM can be maternally transmitted in some families, possibly due to the maternal mitochondrial inheritance. In fact, mitochondrial genes may be plausible causative agents for diabetes, since mitochondrial oxidative phosphorylation plays an important role in glucose-stimulated insulin secretion from beta cells.

MATERIALS AND METHODS

In this report, we screened two Tunisian families with mitochondrial diabetes for the m.3243A>G and the m.14709T>C mutations, respectively, in the tRNA(Leu(UUR)) and the tRNA(Glu) genes.

RESULTS

The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the sequence-specific primers by polymerase chain reaction (SSP-PCR) analysis in the leucocytes and the buccal mucosa in the members of the two families showed the absence of the m.3243A>G mutation and the presence of the heteroplasmic m.14709T>C mutation in the tRNA(Glu) gene in the two tested tissues.

CONCLUSIONS

We conclude that the m.14709T>C mutation in the tRNA(Glu) gene could be a cause of mitochondrial diabetes in Tunisian affected families. In addition, the heteroplasmic loads correlated with the severity and the onset of mitochondrial diabetes in one family but not in the other, suggesting the presence of environmental factors or nuclear modifier genes.

Prevalence of 15 mitochondrial DNA mutations among type 2 diabetic patients with or without clinical characteristics of maternally inherited diabetes and deafness

The aim of the present study is to investigate the prevalence of ten described mitochondrial DNA (mtDNA) mutations in patients with type 2 diabetes, and search for new mutations in four mtDNA genes in a subgroup of patients with characteristics of maternally inherited diabetes and deafness (MIDD). These mutations were investigated in 407 type 2 diabetic patients without characteristics of mitochondrial diabetes ('classical' type 2 diabetes group) and in 38 type 2 diabetic patients with characteristics suggestive of MIDD. Through sequencing of four mtDNA genes in MIDD patients, we selected five others potentially pathogenic mutations that were also screened in the remaining patients. Overall, the frequency of the fifteen analyzed mutations was 36.84% in the MIDD group and 2.45% in the 'classical' type 2 diabetes group (p < 0.001). In conclusion, our study reinforces the importance of mtDNA mutations in the pathogenesis of MIDD.

Novel mutations of mitochondrial DNA associated with type 2 diabetes in Chinese Han population

Mitochondrial single nucleotide polymorphisms (mtSNPs) have been reported to associate with type-2 diabetes mellitus (T2DM), but mtSNPs appear to be considerably different among different populations and regions. To determine mtSNPs in Chinese Han patients with T2DM, the entire sequences of the mitochondrial genomes from 72 T2DM Chinese (59 +/- 4 years) and 50 age-matched healthy subjects (controls) in Chongqing region of Western China were directly sequenced and mtSNPs were analyzed. We found that M8, M9, D, G, R and A haplogroups exist in Chinese Han population and the frequency of haplogroup M9 was significantly higher in patients with T2DM than in the controls (p = 0.0006, OR 0.06 [95% CI 0.008-0.476]). MtSNPs T3394C in NADH dehydrogenase subunit 1 (ND1), G4491A in ND2, T16189C and T16519C were found with significantly higher frequency in patients with T2DM than in the controls (T16189C, p = 0.0045; T16519C, p < 0.0001; T3394C, p = 0.0015; G4491A, p = 0.0015). In contrast, the frequency of C5178A in ND2 and A10398G in ND3 was higher in the controls than in patients with T2DM (C5178A, p = 0.014; A10398G, p = 0.0011). Our results indicate that mtSNPs T3394C, G4491A, T16189C and T16519C show susceptible tendency to T2DM and mtSNPs C5178A and A10398G seem to be genetic factors for against T2DM. These mtSNPs determined in our study is useful and could be used for early diagnosis and prevention of T2DM in Chinese Han population.