The role of catechol-O-methyltransferase and dopamine transporter gene polymorphisms in alcoholism

Alkoholizam je psihijatrijski poremećaj kompleksne etiologije koji nastaje zbog različitih genetičkih i okolišnih čimbenika te njihove međusobne interakcije. Iako su geni dopaminergičkog sustava povezani s alkoholizmom, rezultati istraživanja o povezanosti alkoholizma i polimorfizma zamjene jedne baze Val108/158Met gena za katehol-O-metil transferazu (COMT), ili polimorfizma varijabilnog broja ponavljanja u 15. eksonu gena za dopaminski transporter (DAT1) su oprečni. Cilj ovog rada bio je odrediti postoji li u hrvatskoj populaciji povezanost alkoholizma i specifičnih fenotipova vezanih za alkoholizam s polimorfizmima gena COMT i DAT1. Genotipizirano je 376 ovisnika o alkoholu i 397 zdravih osoba. Nije uočena značajna razlika u učestalosti genotipova i alela COMT i DAT1 između ovisnika o alkoholu i zdravih osoba. Rezultati pokazuju da nije potvrđena hipoteza o utjecaju navedenih polimorfizama na razvoj alkoholizma, ali je pronađena njihova veza s dobi početka prekomjerne uporabe alkohola. Također je pronađena i povezanost polimorfizma COMT s pokušajem suicida, te suicidalnim ponašanjem.Alcoholism is complex psychiatric disorder which develops as a product of genetic and environmental factors and their interaction. Although genes of the dopaminergic system are associated with alcoholism, studies show contradictory data on association of alcoholism with catechol-O-methyltransferase (COMT) Val108/158Met polymorphism or with variable number of tandem repeats polymorphism in the 15th exon of dopamine transporter gene (DAT1). The aim of this study was to determine whether polymorphisms in COMT and DAT1 genes are associated with alcoholism and alcoholism-related phenotypes in Croatian population. The study included 376 subjects with alcohol dependence and 397 control subjects. There was no significant difference in the frequency of the COMT and DAT1 genotypes and alleles between alcoholics and healthy subjects. The results failed to confirm the hypothesis of the association between alcoholism and COMT and DAT1 polymorphisms, but identified their association with beginning of the excessive alcohol use. Also, a relationship between COMT polymorphism and suicidal behavior and suicide attempt was found