Southern Chinese Han Population Research Articles

Association between ECE1 gene polymorphisms and risk of intracerebral haemorrhage.

ObjectiveTo determine whether endothelin converting enzyme-1 (ECE1) gene polymorphisms contribute to susceptibility to intracerebral haemorrhage (ICH) by influencing blood pressure.MethodsThis case–control study enrolled patients with ICH and healthy control subjects from a Southern Han Chinese population. The ECE1 gene polymorphisms rs212528 and rs213045 were genotyped. The association between the genotypes and the risk of ICH was assessed. The effects of these two ECE1 gene polymorphisms on blood pressure were also analysed.ResultsA total of 389 patients with ICH and 404 healthy control subjects participated in the study. There was no significant association between the ECE1 rs212528 and rs213045 polymorphisms and ICH even after adjusting for different confounding variables. In patients with ICH, the systolic blood pressure of patients with the rs212528 AA genotype was significantly lower than that of patients with the AG/GG genotypes.ConclusionsThese results indicated that the ECE1 rs212528 and rs213045 polymorphisms had no major role to play in the genetic susceptibility to ICH, although rs212528 might influence blood pressure in patients with ICH.

Genetic analysis of the aquaporin-4 gene for anti-AQP4 antibody-positive neuromyelitis optica in a Japanese population.

Neuromyelitis optica (NMO) is an inflammatory demyelinating disorder that generally affects the optic nerve and spinal cord. The etiology of this disease is still uncertain, but autoantibodies to aquaporin-4 (AQP4) are specific and pathogenic for NMO. Recent studies show that AQP4 gene variants are associated with NMO. In this study, we assessed the contribution of AQP4 genetic variants to susceptibility to anti-AQP4 antibody (AQP4-Ab)-positive NMO in a Japanese population. The subjects were 16 patients with AQP4-Ab-positive NMO (13 sporadic cases, and 3 familial cases from 2 families) and 255 healthy controls. All coding exons of AQP4 were sequenced and five tag single-nucleotide polymorphisms (SNPs) in AQP4 were genotyped. We also performed an imputation analysis to evaluate the potential association of un-genotyped SNPs in AQP4. Known or novel mutations were not detected in any coding exon regions. The T allele frequency of polymorphism (-810bp (C/T): rs2075575) of the promoter region in patients with AQP4-Ab-positive NMO was significantly higher than that in controls (50.0 vs 25.7%, P=0.0036, Pc=0.018 odds ratio=2.89). No other tag or imputed SNPs were significant. These findings suggest that the T allele of rs2075575 is a risk for AQP4-Ab-positive NMO. However, the results are the opposite of a previous study in the southern Han Chinese population, and therefore further genetic studies are needed to determine the possible contribution of the AQP4 region to development of NMO.

Polymorphism analysis of 20 autosomal short-tandem repeat loci in southern Chinese Han population

To evaluate the value of PowerPlex®21 System (Promega) and study the genetic polymorphism of its 20 short-tandem repeat (STR) loci in southern Chinese Han population. We conducted genotyping experiments using PowerPlex®21 System on 20 autosomal STR loci (D3S1358, D1S1656, D6S1043, D13S317, Penta E, D16S539, D18S51, D2S1338, CSF1PO, Penta D, TH01, vWA, D21S11, D7S820, D5S818, TPOX, D8S1179, D12S391, D19S433 and FGA) in 2367 unrelated Chinese Han individuals living in South China. The allele frequencies and parameters commonly used in forensic science were statistically analyzed in these individuals and compared with the reported data of other populations. The PowerPlex®21 System had a power of discrimination (PD) ranging from 0.7839 to 0.9852 and a power of exclusion (PE) ranging from 0.2974 to 0.8099 for the 20 loci. No significant deviation from Hardy-Weinberg expectations was found for all the loci except for D5S818. This southern Chinese Han population had significant differences in the allele frequencies from 8 ethnic groups reported in China, and showed significant differences at 8 to 20 STR foci from 5 foreign populations. The allele frequency at the locus D1S1656 in this southern Chinese Han population differed significantly from those in the 5 foreign populations and from 3 reported Han populations in Beijing, Zhejiang Province and Fujian Province of China. The neighbor-joining phylogenetictree showed clustering of all the Asian populations in one branch, while the northern Italian and Argentina populations clustered in a separate branch. This southern Chinese Han population had the nearest affinity with the Yi ethnic population in Yunnan Province of China. The 20 STR loci are highly polymorphic in this southern Chinese Han population, suggesting the value of this set of STR loci in forensic personal identification, paternity testing and anthropological study.

CLPTM1L polymorphism as a protective factor for lung cancer: a case-control study in southern Chinese population.

Variants of the cleft lip and palate trans-membrane 1 like (CLPTM1L) gene, located on chromosome 5p15.33, were previously determined to influence lung cancer susceptibility. Here, we performed a case-control study to examine the potential association of CLPTM1L single nucleotide polymorphisms (SNPs) with lung cancer in a Chinese Han population. We selected four SNPs in the CLPTM1L gene that were previously reported to be associated with lung cancer. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of the relationship between each CLPTM1L SNP and lung cancer risk. Allelic model analysis revealed that the minor alleles of all four SNPs were significantly associated with decreased lung cancer risk. Similar significant results were detected using genetic model analysis. In addition, we observed a protective effect of haplotype "TT" in the CLPTM1L gene. Our results verified that certain CLPTM1L polymorphisms are protective factors against lung cancer in a southern Chinese Han population and may be potential diagnostic and molecular markers for lung cancer patients.

Analysis of Association between MAP2K4 Gene Polymorphism rs3826392 and IL-1b Serum Level in Southern Chinese Han Ischemic Stroke Patients

Mitogen-activated protein kinase kinase 4 (MAP2K4) gene acts as the direct upstream activator of c-Jun NH2-terminal kinase pathway, which plays an important role in regulating neuron survival and apoptosis in response to cerebral ischemia. However, the association between MAP2K4 gene polymorphisms and ischemic stroke (IS) has not yet been published. Therefore, this study investigates the association between MAP2K4 gene polymorphism rs3826392 and IS susceptibility, as well as its quantitative traits in Southern Chinese Han population. A total of 816 Chinese patients with IS and 816 age- and sex-matched controls were recruited. Rs3826392 was genotyped using Sequenom MassARRAY iPLEX platform (Sequenom, San Diego, CA, USA). The mRNA expression of MAP2K4 gene in peripheral blood mononuclear cells was detected using reverse transcription-polymerase chain reaction. The levels of serum cytokines, including IL-1b, IL-6, IL-8, IL-12, and tumor necrosis factor-α (TNF-α), were measured by enzyme-linked immunosorbent assay. Significant association was not observed between MAP2K4 gene polymorphism rs3826392 and IS susceptibility in all genetic models (P > .05). A significant difference was found in IL-1b, IL-6, IL-8, and TNF-α serum levels between patients with IS and control groups. MAP2K4 gene polymorphism rs3826392 C/A genotype carriers showed significantly higher IL-1b serum levels compared with AA genotype carriers (P = .029) in patients with IS. MAP2K4 gene polymorphism rs3826392 did not contribute to IS susceptibility, but rs3826392 C/A genotype carriers showed significantly higher IL-1b serum levels. This result suggests that rs3826392 may play a potential role in the IS inflammatory process.

Serum Cytokines Th1, Th2, and Th17 Expression Profiling in Active Lupus Nephritis-IV: From a Southern Chinese Han Population.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by aberrant T cell immune response. Diffuse proliferative lupus nephritis (LN-IV) is the most common, severe, and active form of lupus nephritis. In this study, we investigated the production of Th1, Th2, and Th17 cytokines in prediction of active form of LN-IV. ProcartaPlex multiplex immunoassays panels were used for detection of serum Th1, Th2, and Th17 cytokines profiling. Th1 and Th17 cytokines (IL-18, IFN-γ, IL-12p70, IL-6, and IL-17A) were considerably expressed in the serum of lupus nephritis IV patients in comparison to the healthy control. However, only IL18 and IL6 were higher in class IV versus class III lupus nephritis. Importantly, the ratios of Th1/Th2 (IL-18/IL-4) and Th17/Th2 (IL-17A/IL-4) were significantly elevated in LN-IV when compared with LN-III, LN-V, and healthy controls. Consistently, the serum cytokines IL-18, IL-17A, and IFN-γ were markedly expressed in LN-IV patient glomeruli and interstitial tissue compared to other classes of LN by IHC. ROC further suggests that IL-18 was a potential marker for LN-IV. The data from our study suggests that the early detection and quantification of these cytokines may help in prediction of active form of LN-IV.

Interleukin-6 -572G/C polymorphism and prostate cancer susceptibility.

Strong evidence suggests that cancer-associated inflammation promotes tumor growth and progression, and interleukin-6 (IL6) is an important modulator of inflammation. However, the roles of IL6 and mutations of its corresponding gene in prostate cancer have not been clearly documented. We retrieved data from the Oncomine database concerning IL6 expression in prostate cancer and its role in prostate-specific antigen (PSA) recurrence. We also performed a case-control study of the IL6 -572G/C polymorphism (rs1800796) in 236 sporadic prostate cancer patients and 256 healthy controls from a southern Han Chinese population. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association between rs1800796 and prostate cancer susceptibility. A dual-luciferase reporter assay was used to test the transcriptional activity of the IL6 promoter G and C alleles. IL6 was overexpressed in prostate cancer tissues compared to normal tissues, especially in those with higher Gleason scores. Moreover, elevated IL6 expression was associated with high PSA recurrence rate in Oncomine data. Our case-control study demonstrated that compared with the -572C allele, the -572G allele conferred a borderline increased risk of prostate cancer (OR = 1.31, 95%CI = 0.99-1.74, P = 0.061). This was more pronounced in the subgroup of individuals having never smoked (OR = 1.85, 95%CI = 1.07-3.22). Moreover, the G allele showed increased activity relative to the C allele in the dual-luciferase reporter assay. Our results suggest that the -572G/C polymorphism may be associated with IL6 expression, which in turn plays a role in prostate cancer development.

Identification of rare variants of DSP gene in sudden unexplained nocturnal death syndrome in the southern Chinese Han population.

Sudden unexplained nocturnal death syndrome (SUNDS) is a perplexing disorder to both forensic pathologists and clinic physicians. Desmoplakin (DSP) gene was the first desmosomal gene linked to arrhythmogenic right ventricular cardiomyopathy (ARVC) which was associated with sudden death. To identify the genetic variants of the DSP gene in SUNDS in the southern Chinese Han population, we genetically screened the DSP gene in 40 sporadic SUNDS victims, 16 Brugada syndrome (BrS) patients, and 2 early repolarization syndrome (ERS) patients using next generation sequencing (NSG) and direct Sanger sequencing. A total of 10 genetic variants of the DSP gene were detected in 11 cases, comprised of two novel missense mutations (p.I125F and p.D521A) and eight previously reported rare variants. Of eight reported variants, two were previously considered pathogenic (p.Q90R and p.R2639Q), three were predicted in silico to be pathogenic (p.R315C, p.E1357D and p.D2579H), and the rest three were predicted to be benign (p.N1234S, p.R1308Q, and p.T2267S). This is the first report of DSP genetic screening in Chinese SUNDS and Brugada syndrome. Our results imply that DSP mutations contribute to the genetic cause of some SUNDS victims and maybe a new susceptible gene for Brugada syndrome.

Common Variants in Promoter of ADTRP Associate with Early-Onset Coronary Artery Disease in a Southern Han Chinese Population.

The first genome-wide association study for coronary artery disease (CAD) in the Han Chinese population, we reported recently, had identified rs6903956 in gene ADTRP on chromosome 6p24.1 as a novel susceptibility locus for CAD. The risk allele of rs6903956 was associated with decreased mRNA expression of ADTRP. To further study the correlation of ADTRP expression and CAD, in this study we evaluated the associations of eight common variants in the expression-regulating regions of ADTRP with CAD in the Southern Han Chinese population. Rs169790 in 3’UTR, rs2076189 in 5’UTR, four SNPs (rs2076188, rs7753407, rs11966356 and rs1018383) in promoter, and two SNPs (rs3734273, rs80355771) in the last intron of ADTRP were genotyped in 1716 CAD patients and 1572 controls. The correlations between these loci and total or early-onset CAD were investigated. None of these loci was discovered to associate with total CAD (P > 0.05). However, with early-onset CAD, significant both allelic and genotypic associations of rs7753407, rs11966356 and rs1018383 were identified, after adjustment for risk factors of age, gender, hypertension, diabetes, lipid profiles and smoking (adjusted P < 0.05). A haplotype AGCG (constructed by rs2076188, rs7753407, rs11966356 and rs1018383) was identified to protect subjects from early-onset CAD (OR = 0.332, 95% CI = 0.105–0.879, adjusted P = 0.010). Real-time quantitative reverse transcription polymerase chain reaction assay showed that the risk alleles of the associated loci were significantly associated with decreased expression of ADTRP mRNA. Moreover, the average level of ADTRP mRNA expression in early-onset CAD cases was significantly lower than that in controls. Our results provide new evidence supporting the association of ADTRP with the pathogenesis of early-onset CAD.

High Level Serum Procalcitonin Associated Gouty Arthritis Susceptibility: From a Southern Chinese Han Population.

ObjectivesTo study the serum Procalcitonin (PCT) level in inflammatory arthritis including gouty arthritis (GA), Rheumatoid arthritis (RA), and ankylosing spondylitis (AS) without any evidence of infection were evaluated the possible discriminative role of PCT in gouty arthritis susceptibility in southern Chinese Han Population.Material and MethodsFrom Feb, 2012 to Feb, 2015, 51 patients with GA, 37 patients with RA, 41 patients with AS and 33 healthy control were enrolled in this study with no evidence of infections. The serum level of PCT (normal range < 0.05 ng/ml) was measured by electrochemiluminescence immunoassay (ECLIA). Disease activity was determined by scores of VAS (4.07 ± 1.15), DAS28 (4.97 ± 1.12), and ASDAS (2.97 ± 0.81) in GA, RA and AS groups respectively. Other laboratory parameters such as, serum creatinine (CRE), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), uric acid (UA) and white blood cells (WBC) were extracted from medical record system.ResultsSerum PCT level was predominantly higher in gouty arthritis than in RA and AS patients, especially in the GA patients with tophi. PCT was significantly positively correlated with VAS, CRP and ESR in gouty arthritis and CRP in AS. PCT also had positive correlation-ship with ESR, DAS28 and ASDAS in RA and AS patients respectively, but significant differences were not observed.ConclusionsThese data suggested that PCT is not solely a biomarker for infection, but also an indicator in inflammatory arthritis, especially in gouty arthritis.

Human Leukocyte Antigens-B and -C Loci Associated with Posner-Schlossman Syndrome in a Southern Chinese Population.

The etiology of Posner-Schlossman syndrome (PSS) remains unknown. The association of human leukocyte antigens (HLA) allelic diversity with PSS has been poorly investigated. To evaluate the association of allelic polymorphisms of class I HLA-A, -B and -C and class II HLA-DRB1 and -DQB1 with PSS, 100 unrelated patients with PSS and 128 age- and ethnically matched control subjects were recruited from a southern Chinese Han population. Polymorphisms in exons 2–4 for HLA-A, -B, -C loci, exon 2 for HLA-DRB1 and exons 2,3 for HLA-DQB1 were analyzed for association with PSS at allele and haplotype levels. The allele frequency of HLA-C*1402 in PSS patients was significantly higher than that in controls (P = 0.002, OR = 4.12). This association survived the Bonferroni correction (Pc = 0.04). The allele frequency of HLA-B*1301 in PSS patients was lower than that in the control group (P = 0.003, OR = 0.21), although this association did not survive the Bonferroni correction (Pc = 0.16). In PSS patients, the haplotype frequencies of HLA-A*1101~C*1402 and B*5101~C*1402 were higher than that in controls (P = 0.03, OR = 4.44; P = 0.02, OR = 3.20; respectively), while the HLA-B*1301~C*0304 was lower than that in controls (P = 0.007, OR = 0.23), although these associations did not survive the Bonferroni correction (Pc > 0.16). This study for the first time demonstrated that polymorphisms at the HLA-B and HLA-C loci were nominally associated with PSS in the southern Chinese Han population. Our results suggest that HLA-C*1402, A*1101~C*1402 and B*5101~C*1402 might be risk factors for PSS, whereas HLA-B*1301 plus B*1301~C*0304 might be protective factors against PSS, but even larger datasets are required to confirm these findings. Findings from this study provide valuable new clues for investigating the mechanisms and development of new diagnosis and treatment for PSS.

Association Between TRAF6 Gene Polymorphisms and Susceptibility of Ischemic Stroke in Southern Chinese Han Population.

The tumor necrosis factor receptor-associated factor 6 (TRAF6) gene encodes a protein that acts downstream of the Toll-like receptor (TLR) pathway. TLRs activate inflammatory cascades and mediate inflammatory injury after cerebral ischemia. However, the role of TFAR6 gene polymorphisms in ischemic stroke (IS) remains unknown. This study aims to investigate the associations of TRAF6 gene polymorphisms with susceptibility to IS and IS-related quantitative traits in Southern Chinese Han population. A total of 816 IS cases and 816 age- and gender-matched controls were included. Two variants of the TRAF6 gene (rs5030411 and rs5030416) were genotyped using the Sequenom MassARRAY iPLEX platform. Our study showed that rs5030416 was significantly associated with increased susceptibility to IS in the additive model [ORadj 1.25(1.04-1.51), P adj = 0.019, P Bc = 0.038] and dominant model [ORadj 1.23(1.04-1.60), P adj = 0.021, P Bc = 0.042] after adjusting by age and sex and applying a Bonferroni correction. No significant association was found between rs5030411 and IS susceptibility (all P > 0.05). The haplotype rs5030416 (allele C)-rs5030411 (allele C) was significantly associated with IS susceptibility (P adj = 0.015). Moreover, a significant association of rs5030411 with TC levels in IS patients under the additive model [β 0.16(0.01-0.30), P adj = 0.034] and recessive model [β 0.45(0.12-0.78), P adj = 0.007] was observed after adjustment by age and sex. This association remained statistically significant under the recessive model (P Bc = 0.042) after Bonferroni correction. Our results suggest that TRAF6 gene polymorphisms may be involved in the pathogenesis of IS.

The HLA-B*4601-DRB1*0901 haplotype is positively correlated with juvenile ocular myasthenia gravis in a southern Chinese Han population.

Myasthenia gravis (MG) is a sporadic disorder that has been increasingly linked to inherited genetic factors. Previous studies have demonstrated that human leukocyte antigen (HLA) plays an important role in the pathogenesis of MG. We determined the genotypes of the HLA-A, B, and DRB1 alleles in 257 southern Chinese Han MG patients using polymerase chain reaction sequence-based typing (PCR-SBT). The allele frequencies in the MG patients were compared to 292 healthy controls using the case-control method. HLA-A*0207, HLA-B*4601, HLA-DRB1*0403, HLA-DRB1*0901, and HLA-DRB1*1602 were more frequent in juvenile ocular MG patients than controls. HLA-DRB1*0701 was significantly reduced in the juvenile ocular MG group compared with controls. HLA-A*0207-B*4601, HLA-B*4601-DRB1*0403, HLA-B*4601-DRB1*0901, and HLA-B*4601-DRB1*1602 were found to be in strong linkage disequilibrium in juvenile ocular MG patients. Within the MG patients, there was a strong positive association between HLA-B*4601-DRB1*0901 and juvenile ocular MG patients, and the value of odds ratios (OR) decreased as the disease became more severe and the age of onset increased. We believe this could be the main heredity phenotype in juvenile ocular MG patients from southern China and may be a clinical marker to predict the severity of the disease.

Associations between polymorphisms in the SYK promoter and susceptibility to sporadic colorectal cancer in a Southern Han Chinese population - a short report.

Down-regulated expression of the putative tumor suppressor gene spleen tyrosine kinase (SYK) is strongly associated with the development of various cancers, including colorectal cancer (CRC). SYK gene promoter polymorphisms have been shown to be involved in the pathogenesis of multiple malignant tumors. In this study, we investigated associations of SYK gene promoter polymorphisms with the susceptibility to colorectal cancer development in a Southern Han Chinese population. SNPs in the promoter region of the human SYK gene were identified using in silico analysis tools, linkage disequilibrium analysis, and a search for likely transcription factor binding sites via TFSEARCH in the NCBI SNP database (gene ID: 6850). Based on this information, -803A>T and -534T>C were selected as candidates for further analysis. TaqMan-MGB probe analyses were performed in 567 CRC patients and 569 age- and gender-matched healthy controls for SYK gene promoter genotyping. Associations between CRC risk and SNPs were estimated using an unconditional logistic regression model, and environmental risk factors were included in a multivariate logistic regression model for correction. The frequencies of the TA and TT genotypes and the T allele of the -803A>T SNP were found to be significantly higher in the CRC patients compared to the healthy individuals of the control group (P=0.020, 0.023, and 0.013, respectively). Synergistic effects between -803A>T genotypes (i.e., TA+TT) and age (≤60 years; P=0.039), male gender (P=0.011), smoking (P=0.005), drinking alcohol (P=0.002), and high BMI (≥24.0 kg/m2; P=0.009) were found to increase the risk to develop CRC by stratified analyses. The SYK -803 A>T genotypes TA and TT are independent risk factors for CRC development in Han Chinese in Southern China, and an association with TA+TT genotypes appears predominant among younger patients, male patients, patients with a high BMI, and patients who smoke or drink alcohol.

Association of HLA-DPA1 and -DPB1 polymorphisms with Posner-Schlossman syndrome among southern Chinese Han population

To assess the association of HLA-DPA1 and -DPB1 polymorphisms with Posner-Schlossman syndrome (PSS) in southern Chinese Han population. A total of 100 randomly selected PSS patients of southern Chinese Han origin were served as the experimental group, while 128 unrelated healthy blood donors of the same origin were served as the control group. All samples were subjected to sequencing-based typing (SBT) for exon 2 of HLA-DPA1 and -DPB1 loci in both directions. HLA genotype was assigned using an Assign 3.5 HLA SBT software. The allele frequencies and haplotype frequencies of HLA-DPA1 and -DPB1 of the two groups were compared. x² test, P value and odds ratio (OR) value were calculated. Six HLA-DPA1 alleles in the experimental group and 4 HLA-DPA1 alleles in the healthy control group were identified. The allelic frequency for HLA-DPA1*02:01 in the experimental group was significantly lower than the control group (4.50% vs. 12.109%; x²=8.124, P=0.004). Sixteen HLA-DPB1 alleles were identified in both the experimental and control groups. The allelic frequencies for HLA-DPB1*14:01 and - DPB1*17:01 in the experimental group were significantly lower than those of the control group ( DPB1*14:01: 1.00% vs. 4.688%, x²=5.130, P=0.024; DPB1*17:01: 0% vs. 2.344%, x²=3.897, P=0.048). The DPA1-DPB1 haplotypes for the experimental and control groups were 23 and 25, respectively. The haplotype frequencies for both DPA1*02:01- DPB1*14:01 and DPA1*02:01- DPB1*17:01 were significantly lower than those of the control group. DPA1*02:01- DPB1*14:01 and DPA1*02:01- DPB1*17:01 haplotypes may provide considerable protection effect against PSS in the southern Chinese Han population.

A Case-Control Study of Sudden Unexplained Nocturnal Death Syndrome in the Southern Chinese Han Population

To study the epidemiological characteristics of sudden unexplained nocturnal death syndrome (SUNDS) in the southern Chinese Han population during 2007 to 2013, we gathered 879 SUNDS victims from Dongguan City and in the Longgang District in Shenzhen City as the case group then selected 879 all-cause death cases, adopting a 1:1 pair method, as the control group I and collected 8142 all-cause death cases from the Bao'an District in Shenzhen City as the control group II, simultaneously. Case information collected was statistically analyzed. The annual incidence of SUNDS is 1.02 and 2.23 per 100,000 person-years for Dongguan City and in the Longgang District, respectively. The number of male and female victims is drastically different, with a ratio of 13.92:1, whereas the incidence between the 2 sexes is significantly different (χ2 = 78.734, P < 0.01), with an odds ratio value of 11.32 (95% confidence interval, 5.75-22.28). The age of death of SUNDS cases ranges from 17 to 55 years with a median age of 35 years; furthermore, the difference of distribution of age of death between the SUNDS victims and the all-cause death population is significant (χ2 = 767.12, P < 0.001). The birthplace of SUNDS victims is distributed throughout 27 provinces of China, but the difference between the SUNDS victims and the all-cause death population is not significant (χ2 = 27.273, P > 0.05). The monthly incidence of SUNDS is relatively higher from March to June, whereas the difference of monthly distribution between SUNDS victims and all-cause death population is significant (χ2 = 9.869, P < 0.05), with an odds ratio value of 1.42 (95% confidence interval, 1.14-1.76). Although the majority of SUNDS occurred during midnight sleep, they were mostly discovered from 7 to 9 am once the inmates or spouses woke in the morning. A total of 97.74% of the SUNDS victims were blue-collar factory workers with a high-intensity labor and poor education background. This investigation confirmed the stability of epidemiological characteristics of SUNDS in South China and implicated that risk factors of this fatal disease still exist. The efficient strategy of early identification such as molecular diagnosis for SUNDS is extremely urgently required.

Association of GWAS-Supported Variants rs2200733 and rs6843082 on Chromosome 4q25 with Ischemic Stroke in the Southern Chinese Han Population.

Genome-wide association studies (GWAS) have revealed two single-nucleotide polymorphisms (SNPs) on chromosome 4q25, rs2200733, and rs6843082, associated with ischemic stroke (IS) in Caucasians. However, subsequent validation studies have remained controversial. The current study aims to evaluate the associations between rs2200733, rs6843082, and IS in the southern Chinese Han population. A total of 1632 subjects were recruited in this case-control study. Genotyping for rs2200733 and rs6843082 was conducted in the Sequenom MassARRAY iPLEX platform. The genetic association of the rs2200733 and rs6843082 polymorphisms with IS was estimated using the PLINK program. Our results show that the SNP rs2200733 and rs6843082 have no significant associations with IS in additive, dominant, recessive, and allelic models (all p > 0.050). However, the results also indicate that the rs2200733 polymorphism is associated with systolic blood pressure (SBP) in IS patients in both the additive model (p adj = 0.002) and the recessive model (p adj = 0.002) after correcting for age. Meanwhile, the rs6843082 polymorphism showed a significant association with serum total cholesterol (TC) in IS individuals in the additive model (p adj = 0.017) and the dominant model (p adj = 0.023). These findings suggest that the SNP rs2200733 and rs6843082 on chromosome 4q25 may be not associated with IS susceptibility in southern Han Chinese. As for IS-related quantitative traits, the rs2200733 and rs6843082 polymorphisms might influence SBP and TC in IS patients, respectively.

NKG2C copy number variations in five distinct populations in mainland China and susceptibility to nasopharyngeal carcinoma (NPC)

In this study, copy number variation (CNV) of NKG2C gene was investigated in 1129 normal, unrelated individuals representing two southern Chinese Han populations (Hunan Han and Guangdong Han), two northern Chinese populations (Inner Mongolia Han and Inner Mongolia Mongol) and one southeastern Chinese Han population (Fujian Han) using polymerase chain reaction-sequence-specific priming (PCR-SSP) method. CNV of NKG2C gene did not vary significantly among the five Chinese populations, with NKG2C gene deletion showing a frequency ranging from 0.2031 to 0.2688. Compared with worldwide ethnic groups, very significant difference was observed between the five Chinese populations and the Mexican mestizos (all Pcorrected=0.0025), and between the Fujian Han population and the German population (Pcorrected=0.005). We further examined CNV of NKG2C and HLA-E allelic distribution in 653 patients afflicted with nasopharyngeal carcinoma (NPC) in Hunan province. Neither CNV of NKG2C nor HLA-E was associated with NPC. There was a trend of reduced NPC risk in individuals who were homozygous for both HLA-E∗01:03 and NKG2C deletion (0.46% vs. 2.51%, P=0.0076, Pcorrected=0.0684, OR (95% CI)=0.1794 (0.0473–0.6809)). Taken together, our results suggest that NKG2C deletion and HLA-E signalling pathway does not play a major role in determining genetic susceptibility to NPC.

Association of Deoxyribonuclease I Gene Polymorphisms with Graves’ Disease in the Chinese Han Population

Background: This study aimed to investigate the association between the single nucleotide polymorphism (SNP) rs1053874 in the deoxyribonuclease I (DNASE1) gene and Graves’ disease (GD) in the Han Chinese population. Methods: Polymerase chain reaction-restriction fragment length polymorphism analysis and direct sequencing were used to identify the distribution of the SNP rs1053874 in the DNASE1 genes from 284 GD patients and 203 healthy controls, and associations between clinical manifestations of GD and the observed genotype and allele frequencies at the DNASE1 gene were analyzed. Results: In the Han Chinese population, there were significant differences between the GD groups and the controls with respect to genotype and allele frequencies associated with theSNPrs1053874. The risk of GD was greater among carriers of the G allele than non-carriers (OR=0.65, 95% CI: 0.49- 0.86). There were significant differences in genotype and allele frequencies between the GD patients with a history of relapse and the GD patients without history of relapse; furthermore, the G allele of the SNP rs1053874 was associated with relapse in GD patients. Conclusion: This study confirmed that the DNASE1 gene may be a GD susceptibility gene in the in the Southern Chinese Han population. The G allele at the rs1053874 SNP would be a direct genetic risk factor for GD in this population. Furthermore, this allele may be associated with disease relapse.

Rapid identification of apolipoprotein E genotypes by high-resolution melting analysis in Chinese Han and African Fang populations.

Apolipoprotein E (APOE) gene polymorphism can affect APOE gene transcription, serum lipid levels and repair of tissue damage, which could place individuals at serious risk of cardiovascular disease or certain infectious diseases. Recently, high-resolution melting (HRM) analysis was reported to be a simple, inexpensive, accurate and sensitive method for the genotyping or/and scanning of rare mutations. For this reason, an HRM analysis was used in the present study for APOE genotyping in the Southern Chinese Han and African Fang populations. A total of 100 healthy Southern Chinese Han and 175 healthy African Fang individuals attended the study. Polymerase chain reaction-DNA sequencing was used as a reference method for the genotyping of these samples. The six APOE genotypes could all be rapidly and efficiently identified by HRM analysis, and 100% concordance was found between the HRM analysis and the reference method. The allele frequencies of APOE in the Southern Chinese Han population were 7.0, 87.5 and 5.5% for ɛ2, ɛ3 and ɛ4, respectively. In the African Fang population, the allele frequencies of APOE were 24.3, 65.7 and 10.0% for ɛ2, ɛ3 and ɛ4, respectively. A statistically significant difference was found between the allele frequencies between the populations (P<0.05). In conclusion, the present study revealed the molecular characterization of APOE gene polymorphism in the Han population from the Chaozhou region of Southern China and the Fang population from Equatorial Guinea. The findings of the study indicated that HRM analysis could be used as an accurate and sensitive method for the rapid screening and identification of APOE genotypes in prospective clinical and population genetic analyses.