title: Genetic variants in the promoters of let-7 family are associated with an increased risk of major depressive disorder.
abstract: BACKGROUND
  Let-7 family plays a critical role in the pathogenesis of major depressive disorder (MDD). Genetic polymorphisms in the promoters of miRNA may influence individual׳s susceptibility to diseases. The purpose of this study was to investigate the association between rs10877887 and rs13293512 polymorphisms in the promoters of let-7 family and the risk of MDD.
  
  
  METHODS
  Polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing assays were used to analyze the rs10877887 and rs13293512 polymorphisms in 237 MDD patients and 296 controls.
  
  
  RESULTS
  We found that the rs10877887 CC genotype was associated with an increased risk of MDD (CC vs. TT: OR=1.73, 95% CI, 1.04-2.86, P=0.03, and CC vs.
  OR=1.74, 95% CI, 1.08-2.80, P=0.02, respectively). Similarly increased risk was also observed for the rs13293512 (CC vs. TT: OR=1.83, 95% CI, 1.12-2.99, P=0.015; CC vs.
  OR=1.84, 95% CI, 1.20-2.81, P=0.005; and C vs. T: OR=1.32, 95% CI, 1.03-1.68, P=0.03, respectively). Stratification analysis showed that patients with the rs13293512 TC and CC genotypes had a 2.29 and 2.56-fold increased risk of MDD recurrence after treatment (TC vs. TT: 95% CI, 1.23-4.25, P=0.008; CC vs. TT: 95% CI, 1.25-5.23, P=0.009, respectively).
  
  
  CONCLUSIONS
  Relatively small sample size and hospital-based study design may influence the results.
  
  
  CONCLUSIONS
  Our findings suggest that the rs10877887 and rs13293512 polymorphisms may be related to the development of MDD.
authors.affiliation: Department of Forensic Psychiatry, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, PR China.
authors.forename: Yundan
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Mental Health Hospital of Jining, Jining, Shandong 272051, PR China.
authors.forename: Gaofeng
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Central Laboratory, Yunnan University of Chinese Traditional Medicine, Kunming, Yunnan 650500, PR China.
authors.forename: Ruifen
authors.initials: R
authors.lastname: Sun
authors.affiliation: Criminal Detachment of Chengdu Public Security Bureau, Chengdu, Sichuan 610017, PR China.
authors.forename: Yuanyi
authors.initials: Y
authors.lastname: Mao
authors.affiliation: Department of Forensic Psychiatry, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, PR China.
authors.forename: Gangqin
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Forensic Psychiatry, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, PR China.
authors.forename: Xueyan
authors.initials: X
authors.lastname: Chen
authors.affiliation: Laboratory of Molecular and Translational Medicine, West China Institute of Women and Children׳s Health; West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China. Electronic address: gaolinboscu@163.com.
authors.forename: Linbo
authors.initials: L
authors.lastname: Gao
authors.affiliation: Department of Forensic Psychiatry, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, PR China. Electronic address: huzeqing@126.com.
authors.forename: Zeqing
authors.initials: Z
authors.lastname: Hu
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000235:genetics*; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011401:Promoter Regions, Genetic
chemical_list: D035683:MicroRNAs; C487931:mirnlet7 microRNA, human
keywords: Let-7; Major depressive disorder; Polymorphism; Promoter