Inverse association between obesity predisposing FTO genotype and completed suicide

• Published in: PloS one 2014-09, Vol.9 (9), p.e108900
• Main Authors: Chojnicka, Izabela, Fudalej, Sylwia, Walczak, Anna, Wasilewska, Krystyna, Fudalej, Marcin, Stawiński, Piotr, Strawa, Katarzyna, Pawlak, Aleksandra, Wojnar, Marcin, Krajewski, Paweł, Płoski, Rafał
• Format: Article
• Language: English
• Subjects: Addictions; Adult; Alcoholic beverages; Alcoholism; Alcoholism - complications; Alcoholism - genetics; Alleles; Alpha-Ketoglutarate-Dependent Dioxygenase FTO; Behavior disorders; Biology and Life Sciences; Body mass; Body mass index; Body size; Deoxyribonucleic acid; DNA; DNA methylation; Drug addiction; Drug dependence; Ethanol; Female; Fto gene; Gene expression; Gene polymorphism; Genetic aspects; Genetic Association Studies; Genetic polymorphisms; Genetic Predisposition to Disease; Genetics; Genomes; Genotype & phenotype; Human remains; Humans; Male; Medicine and Health Sciences; Mental depression; Obesity; Obesity - complications; Obesity - genetics; Polymorphism; Polymorphism, Single Nucleotide; Population; Proteins - genetics; Psychiatry; Risk factors; Studies; Suicide; Suicide genes; Suicides & suicide attempts; Systematic review
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0108900

The A allele of rs9939609 in the FTO gene predisposes to increased body mass index (BMI) and obesity. Recently we showed an inverse association between the obesity related A allele of rs9939609 and alcohol dependence which was replicated by others. Since this finding raises a possibility that FTO may be associated with other psychiatric phenotypes, we aimed to examine association of rs9939609 with completed suicide. We genotyped rs9939609 in 912 suicide victims and 733 controls using TaqMan approach. We observed an inverse association between suicide and the rs9939609 A allele (OR = 0.80, P = 0.002, Pcor = 0.006) with genotype distribution suggesting a co-dominant effect. Given the link between alcoholism and suicide under influence of alcohol reported in Polish population, confounding by alcohol addiction was unlikely due to apparently similar effect size among cases who were under influence of ethanol at the time of death (OR = 0.76, P = 0.003, N = 361) and those who were not (OR = 0.80, P = 0.007, N = 469). The search for genotype-phenotype correlations did not show significant results. In conclusion, our study proves that there is an inverse association between rs9939609 polymorphism in FTO gene and completed suicide which is independent from association between FTO and alcohol addiction.