The combined effects of the 5-HTTLPR and 5-HTR1A genes modulates the relationship between negative life events and major depressive disorder in a Chinese population.
BACKGROUND
Serotonin transporter (5-HTT) and 5-HT receptor (5-HTR) involved in the neurotransmission of 5-HT may play an important role in the development of major depression disorder (MDD). Several lines of evidence suggested that the gene-environment interaction may confer susceptibility to depression. The aim of this study is to analyze the combined effect of four serotonin-related genes and two environmental factors on MDD in a Chinese population.


METHODS
This study recruited a total of 401 patients with MDD and 391 age- and gender-matched control subjects. They were all Chinese Han origin. Negative life events and objective social supports were assessed using standard rating scales. Six polymorphisms in the four serotonin-related genes (5-HTT, 5-HTR1A, 5-HTR1B and 5-HTR2A) were selected to detect. The analyses of the gene-environment interactions were performed by the Multifactor Dimensionality Reduction (MDR).


RESULTS
Allelic associations between patients with MDD and controls were observed for the polymorphism of 5-HTTLPR and for rs6295 at the 5-HTR1A locus. The 5-HTTLPR polymorphism was associated with negative life events on MDD. A three-way interaction between the 5-HTTLPR polymorphism, rs6295 and negative life events on MDD was found in the individuals aged from 20 years to 29 years. In addition, the individuals carrying the L/L genotype of 5-HTTLPR could be susceptible to MDD when exposed to negative life events.


CONCLUSIONS
The 5-HTTLPR polymorphism may modify the interaction between negative life events and MDD in the Chinese population. To our knowledge, this is the first report on the combined effect for the 5-HTTLPR polymorphism and 5-HTR1A genes on modifying the response to negative life events conferring susceptibility to MDD in the 20-29 year group.
Department of Psychiatry, First Hospital of Shanxi Medical University, Taiyuan, 030001, PR China.
Kerang
K
Zhang
Qi
Q
Xu
Yong
Y
Xu
Hong
H
Yang
Jinxiu
J
Luo
Yan
Y
Sun
Ning
N
Sun
Shan
S
Wang
Yan
Y
Shen
D000328:Adult; D000483:Alleles; D044466:Asian People / Q000235:genetics*; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology*; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008016:Life Change Events; D008297:Male; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D044382:Population Groups / Q000235:genetics / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D044282:Receptor, Serotonin, 5-HT1A / Q000235:genetics*; D044302:Receptor, Serotonin, 5-HT1B / Q000235:genetics; D012701:Serotonin / Q000235:genetics; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012944:Social Support; D055815:Young Adult
D044302:Receptor, Serotonin, 5-HT1B; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D044282:Receptor, Serotonin, 5-HT1A; D012701:Serotonin