Association of DRD3, COMT, and SLC6A4 Gene Polymorphisms with Type 2 Diabetes in Southern Chinese: A Hospital-Based Case-Control Study.
OBJECTIVE
The aim of this study was to assess the associations of six single nucleotide polymorphisms (SNPs) of three genes (DRD3, COMT, and SCL6A4) with type 2 diabetes mellitus (T2DM) in Southern Chinese.


METHODS
Five hundred ninety-five cases with T2DM and 725 healthy controls of Han origin were recruited from six hospitals in Guangdong Province, Southern China. Fasting serum concentrations of markers of interest (total cholesterol, triglyceride, plasma glucose, etc.) were measured in hospitals. SNP genotyping was performed using a custom-by-design 2-×48-Plex SNPscan™ kit (Genesky Biotechnologies Inc., Shanghai, China). Single-point SNP analysis, haplotype analysis, and SNP-SNP interactions were carried out.


RESULTS
SNP rs4646312 in COMT achieved statistical significance in both allelic association and genotypic association and even after adjusting covariates (odds ratio [OR]=1.26; 95% confidence interval [CI], 1.04-1.53; P=0.021). Two haplotypes consisting of rs4646312 and rs4680 were also significantly associated with T2DM, of which C-G was a protective haplotype for T2DM (OR=0.83; 95% CI, 0.70-0.98; P=0.029), whereas T-A was a risk one (OR=1.23, 95% CI, 1.03-1.46; P=0.022). Interaction analysis identified a significant epistatic effect between rs4680 in COMT and rs2066713 in SCL6A4 after adjusting for covariates (OR=3.59, 95% CI, 1.72-7.48; P=0.001 for dominant-dominant model). However, only the interaction between rs4680 and rs2066713 was significant, and haplotype T-A showed a marginally increased risk after Bonferroni correction.


CONCLUSIONS
The genetic polymorphisms in COMT and SCL6A4 confer significant effects in joint actions to T2DM in Southern Chinese.
1 Department of Epidemiology and Medical Statistics, School of Public Health, and Institute of Medical Systems Biology, Guangdong Medical College , Dongguan, Guangdong, China .
Liangchang
L
Xiu
1 Department of Epidemiology and Medical Statistics, School of Public Health, and Institute of Medical Systems Biology, Guangdong Medical College , Dongguan, Guangdong, China .
Meihua
M
Lin
1 Department of Epidemiology and Medical Statistics, School of Public Health, and Institute of Medical Systems Biology, Guangdong Medical College , Dongguan, Guangdong, China .
Weiwei
W
Liu
1 Department of Epidemiology and Medical Statistics, School of Public Health, and Institute of Medical Systems Biology, Guangdong Medical College , Dongguan, Guangdong, China .
Danli
D
Kong
1 Department of Epidemiology and Medical Statistics, School of Public Health, and Institute of Medical Systems Biology, Guangdong Medical College , Dongguan, Guangdong, China .
Zhenghui
Z
Liu
1 Department of Epidemiology and Medical Statistics, School of Public Health, and Institute of Medical Systems Biology, Guangdong Medical College , Dongguan, Guangdong, China .
Yang
Y
Zhang
1 Department of Epidemiology and Medical Statistics, School of Public Health, and Institute of Medical Systems Biology, Guangdong Medical College , Dongguan, Guangdong, China .
Ping
P
Ouyang
2 Department of Endocrinology and Metabolism, Maoming People's Hospital , Maoming, Guangdong, China .
Yan
Y
Liang
2 Department of Endocrinology and Metabolism, Maoming People's Hospital , Maoming, Guangdong, China .
Shouqiang
S
Zhong
3 Department of Internal Cardiology, the Affiliated Hospital of Guangdong Medical College , Zhanjiang, Guangdong, China .
Can
C
Chen
4 Guanlan People's Hospital , Baoan District, Shenzhen, Guangdong, China .
Xin
X
Jin
5 Shilong Boai Hospital , Dongguan, Guangdong, China .
Xuejin
X
Fan
1 Department of Epidemiology and Medical Statistics, School of Public Health, and Institute of Medical Systems Biology, Guangdong Medical College , Dongguan, Guangdong, China .
Jiheng
J
Qin
1 Department of Epidemiology and Medical Statistics, School of Public Health, and Institute of Medical Systems Biology, Guangdong Medical College , Dongguan, Guangdong, China .
Xiaolei
X
Zhao
1 Department of Epidemiology and Medical Statistics, School of Public Health, and Institute of Medical Systems Biology, Guangdong Medical College , Dongguan, Guangdong, China .
Shaoqi
S
Rao
1 Department of Epidemiology and Medical Statistics, School of Public Health, and Institute of Medical Systems Biology, Guangdong Medical College , Dongguan, Guangdong, China .
Yuanlin
Y
Ding
D000368:Aged; D044466:Asian People / Q000235:genetics*; D001786:Blood Glucose / Q000032:analysis; D016022:Case-Control Studies; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D002681:China; D002784:Cholesterol / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000235:genetics*; D005215:Fasting / Q000097:blood; D005260:Female; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D050637:Receptors, Dopamine D3 / Q000235:genetics*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; C493593:DRD3 protein, human; D050637:Receptors, Dopamine D3; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D014280:Triglycerides; D002784:Cholesterol; C588010:COMT protein, human; D002394:Catechol O-Methyltransferase