Gene variants and serum levels of synaptic vesicle and presynaptic plasma membrane proteins in alcohol dependence and their relationship with impulsivity and temperament

ABSTRACT Background: Exocytosis-related gene variants have been suggested to be associated with externalizing behaviors. Objective: This study aimed to examine VAMP2 26 bp Ins\Del, synaptotagmin XI (Syt11) rs3820594 and 33-bp promoter, Syntaxin 1A (Syn-1A) rs1569061 and SNAP-25 rs1051312 and rs3746544 polymorphisms, their serum levels and their relationship with impulsivity, temperament in individuals with alcohol dependence (AD) and healthy controls (HC). Methods: The study included 107 individuals with AD and 104 HCs. Single-nucleotide polymorphisms (SNPs) were studied with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and serum levels with ELISA. Michigan Alcohol Screening Test (MAST), Barratt Impulsiveness Scale-11 (BIS-11) and Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire (TEMPS-A) were applied. Results: Syn-1A rs1569061 C allele polymorphism was significantly higher in AD group. Syn-1A rs1569061 C allele was associated with 1.5 times increased risk of AD. All serum levels were significantly higher in the HC group. There was a relationship between Syn-1A rs1569061 polymorphism and BIS-11 motor impulsiveness in the AD group; Syt11 rs3820594 polymorphism and BIS-11 total, TEMPS-A depressive, hyperthymia in the HC group. Discussion: In our study, gene variants and serum levels of synaptic vesicle and presynaptic plasma membrane proteins were related to AD, impulsivity and temperament.