Study on genes of the serotonergic system and suicidal behavior: protocol for a case-control study in Mexican population.
BACKGROUND
Suicidal behavior is a leading cause of injury and death worldwide. Several studies have provided a possible relationship between genetic factors and suicidal behavior. Also, these studies have shown evidence for altered serotonergic neural transmission in the pathogenesis of suicidal behavior. In addition, genes pertaining to the serotonergic system have been proposed as candidates to establish biological correlates between suicidal behavior and the serotonergic system. The most studied genes are SCL6A4, HTR2A, HTR2C, HTR1A, HTR1B, TPH-1, and TPH-2. To get a comprehensive understanding of the association with suicidal behavior we will conduct genotype assays studies in a Mexican population.


METHODS
We will conduct a case-control study. The population sample will comprise adolescent and adult patients admitted for attempted of suicide and diagnosed by a psychiatrist. A peripheral blood sample will be taken from all the subjects (cases and controls). Genomic DNA from the leukocytes blood sample will be extracted. The genotypes of interest are distributed in the following genes: SCL6A4, HTR2A, HTR1A, HTR1B, HTR2C, TPH-2 and TPH-1. All the samples will be analyzed using a polymerase chain reaction (PCR) end-point method. We will evaluate the Hardy-Weinberg Equilibrium. The chi-squared test or Fisher's exact test will be used to compare genotype and allele frequencies between control and case groups. The Quanto 1.2 software will measure the sample size of the association. For all the association analyses the level of significance will be set at p = 0.05 and the confidence interval at 95%.


CONCLUSIONS
Suicidal behavior has been increase in Mexico, principally in young population. Our study will demonstrate the association between serotoninergic genes and suicide behavior in Mexican population.
División Académica Multidisciplinaria de Comalcalco, Ranchería Sur, Cuarta Sección, CP 86650 Comalcalco, Tabasco, México. alfonso_tovillaz@yahoo.com.mx.
Carlos Alfonso
CA
Tovilla-Zárate
Thelma Beatriz
TB
González-Castro
Isela
I
Juárez-Rojop
Sherezada
S
Pool García
Martha Patricia
MP
Velázquez-Sánchez
Mario
M
Villar-Soto
Alma
A
Genis
Humberto
H
Nicolini
María Lilia
ML
López-Narváez
María Antonia
MA
Jiménez-Santos
D000293:Adolescent; D000328:Adult; D000483:Alleles; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008800:Mexico; D008875:Middle Aged; D011985:Receptors, Serotonin / Q000235:genetics; D059326:Serotonergic Neurons / Q000502:physiology*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics; D059020:Suicidal Ideation; D009435:Synaptic Transmission / Q000235:genetics*; D014365:Tryptophan Hydroxylase / Q000235:genetics; D055815:Young Adult
D011985:Receptors, Serotonin; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; C497467:TPH1 protein, human; C494784:TPH2 protein, human; D014365:Tryptophan Hydroxylase