Suicide is the cause of death of nearly 10,000 people a year in France. This is one of the highest rates in Europe. Men are much more affected than women. What if suicide had a genetic and hereditary origin?
A new study published in JAMA Psychiatry he wondered if there was land geneticgenetic for suicide, particularly for suicidal thoughts and behaviour. This large-scale study, which began in 2011 and is ongoing, included 633,778 US military veterans. The panel included 57,152 women and 576,626 men, 121,118 people of African ancestry, 8,285 of Asian ancestry, 452,767 of European ancestry, and 51,608 people of Hispanic ancestry. Data from their military medical records were consulted: 121,211 people suffered from suicidal thoughts and behaviors, equal to 19.1%.
What is a GWAS?
Each of us has a genomegenome made up of about 3 billion base pairs. Between two people, there is a base pair difference in approximately every 1000 base pairs. These differences are called polymorphisms (or SNPs for single nucleotide polymorphism, in English). It is thanks to SNPSNP that we are all different: size, face, colorcolor of hair… but also susceptibility to the development of certain diseases. A GWAS (Genome Wide Association Study) allows you to analyze the SNPs of a large number of people to compare them with each other and establish whether a SNP is correlated with a specific disease, here suicidal thoughts and behaviors.
Genes that predispose to suicide
Analysis of the results showed that more than 200 SNPs were associated with suicidal thoughts and behaviors. These 200 SNPs are found in seven different regions (chromosome 2, 6, 9, 11, 14, 16 and 18). Most of it was on intronic, therefore non-coding regions (lacking GenoaGenoa). In all, four genes — ESR1, DRD2, TRAF3, DCC — could be associated with suicidal thoughts and behaviors. ESR1 is a receptor for estrogenestrogen ; this gene has already been linked syndromesyndrome trauma and depression. DRD2 is a dopamine receptor; has already been associated with schizophreniaschizophrenia, ADHD, mood disorders and alcoholism. TRAF3 has been linked to substance abuse and ADHD. Finally, DCC would have a link with psychiatric disorders. These genes are mainly expressed in the brain and pituitary tissues.
More work is now needed to understand how these genes influence suicidal thoughts. The next step could be the development of targeted therapies to prevent suicide risk in genetically predisposed people, especially during potentially life-triggering events. The authors hypothesize that the lithiumlithiuma reference treatment to reduce the risk of suicide, would for example modulate the expression of TRAF3.
