Serotonin transporter gene (5-HTT) polymorphism and major depressive disorder in patients in Bogotá, Colombia

Abstract

Introduction:The 5-HTT short allele has been controversially associated with an increased risk of major depressive disorder. Objective: To determine the association of 5-HTT short allele with major depression in Bogotá, Colombia. Materials and methods: We carried out a study of cases (n=68) matched 1:1 with controls by gender and age (±5 years). Major depression was diagnosed using the Mini-International Neuropsychiatric Interview, and 5-HTT polymorphism using PCR. Results: Females were predominant (82.4%). The S (short) allele predominated in cases compared with controls (S: 72.1% vs. 63.2; L (long): 27.9% vs. 36.8%), and the SL genotype was more frequent in cases (SL: 45.6% vs. 36.8%; LL: 27.9% vs. 36.8%; SS: 26.5% vs. 26.5%), although not significantly. There were significant differences in those under age 37, with a predominance of the S allele in cases (p=0.038; OR=2.75; 95% CI: 0.88-8.64). Multivariate analysis, adjusted for comorbid anxiety disorders, showed a significant association of major depression with the SL genotype (p=0.049; OR=3.20; 95% CI: 1.00-10.23); the S allele was close to statistical significance (p=0.063; OR=2.94; 95% CI: 0.94-9.13), and it was statistically significant in cases under 37 years of age (p=0.026; OR=10.79; 95% CI: 1.32-80.36). Conclusions: The SL genotype was associated with major depressive disorder in patients of all ages. The S allele was significantly associated with major depressive disorder in patients under age 37, adjusted for comorbid anxiety disorders.

A Systematic Review of Candidate Genes for Major Depression

“…However, the results of those studies were conflicting. For example, some studies with various samples showed positive association for polymorphisms of SLC6A4 [22,[46][47][48][49][50][51][52][53] while others did not confirm such findings [54][55][56][57][58]. The same tendency was seen for the polymorphisms of SLC6A2 [59][60][61], which may indicate a possibility of false positive results.…”

“…Two studies [15,16] delivered results of meta-analyses, in which two SNPs showed significance. Four studies found significant associations only after population stratification by gender: in the women subgroup [17,18], in the men subgroup [19,20]; one study enrolled only female participants [21]; and one study presented significant results in a particular age group of 37 years or older participants [22]. The genotyping methods and main tests for statistical analyses used in the studies are summarized in Table S2 (Table S2: Summary of genotyping and statistical methods used in the eligible studies).…”

Exceso de peso y depresión asociados al Polimorfismo del Gen Transportador de la Serotonina (5-HTTLPR): Una revisión sistemática

“…La DP es una enfermedad mental común que se caracteriza con bajo ánimo, pérdida de interés o placer, energía disminuida, sentimientos de culpa o baja autoestima, alteraciones del sueño o apetito, y mala concentración (5) . Un factor relacionado al desarrollo de síntomas depresivos es la variación genética o polimorfismo de la región promotora del gen transportador de la serotonina (5-HTTLPR) (6) . Un polimorfismo es una variación en la secuencia de un lugar determinado del ADN en los cromosomas de los individuos de una población (7) .…”