Background
Hypothalamic-pituitary-adrenal axis gene variants and childhood trauma (CT) are considered risk factors for suicide attempt (SA). The aim of the present study was analyzed gene x environment (GxE) interaction of
NR3C1, NR3C2
, and CT, and
NR3C1
and
NR3C2
gene expression in the development of SA with CT.
Participants and Methods
A total of 516 psychiatric Mexican patients from Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz. Among them, 274 had SA at least once and 242 had not SA. Genetic variants of
NR3C1
and
NR3C2
were genotyped in all the patients, of which were obtained the CT information from medical records. Additionally, the gene expression of
NR3C1
and
NR3C2
was also analyzed for a subsample of 96 patients, obtaining the TC information from Childhood Trauma Questionnaire (CTQ).
Results
The analysis showed a GxE interaction of
NR3C1, NR3C2
, and CT (OR=2.8, 95% CI [1.9–3.9],
p
<0.0001). Interactions were also observed with neglect (OR=2.1, 95% CI [1.4–3.1],
p
<0.0001), emotional abuse (OR=2.1, 95% CI [1.5–3],
p
<0.0001), and sexual abuse (OR=2.4, 95% CI [1.4–2.9],
p
<0.0001) in the prediction of SA. The analysis of gene expression identified an overexpression of
NR3C1
in SA patients with high scores for physical and sexual abuse (
p
<0.0001;
p
<0.0006, respectively) and emotional neglect (
p
=0.014). An underexpression was observed of
NR3C2
, associated with high scores of trauma subtypes (p<0.0001) except physical neglect. Additionally, we observed an overexpression of
NR3C1
gene in patients with SA carriers of A allele of rs6191 (p=0.0015). Also, overexpression of
NR3C1
gene in carriers of G allele of rs6198 and underexpression of
NR3C2
gene in carriers of G allele of rs5522 (p<0.0001).
Conclusion
Our findings suggest that genetic variants of
NR3C1
and
NR3C2
differentially affect expression levels, increasing the susceptibility to SA in psychiatric patients with a history of CT.