Allelic Variants on SLC6A3 Neurotransmitter Gene and Their Relationship with Personality Traits Scales in Egyptian Athletes

Human dopamine transporter gene (SLC6A3) is one of the neurotransmission genes that plays an important role in controlling the behavior and psychological reactions toward various physical activities. The aim of the present study is to evaluate the associations between SLC6A3 3’-UTR VNTR (3’VNTR) genotypes and eight personality traits in Egyptian athletes. One hundred athletes (50 males and 50 females) and one hundred non-athletes participated in this investigation either in individual or team games. The Freiburg Personality inventory-Revised questionnaire was applied to athletes to evaluate personality traits according to the scale, at a scheduled time, using descriptive analysis. Genotyping for SLC6A3 3’-UTR VNTR polymorphism in athletes was realized to detect the different genotypes by PCR amplifications using desired primers. Three different genotypes of the 3’VNTR polymorphism; namely (9/9), (9/10), (10/10) were identified. The 9/10 and 10/10 genotypes of SLC6A3 gene were significantly higher in players than those in the control group. There were no statistically significant differences in personality traits values among males and females. The Cronbach’s alpha stability coefficient for four items is higher than 0.7 suggesting that these items (Neuroticism, Aggressiveness, Depression and Excitability) have a good reliability and support the used personality dimensions for this investigation. Our findings revealed a significant association between the genotypes of 3’VNTR and the personality traits in Egyptian athletes. These data shed light on the role of SLC6A3 gene in athletes’ behavioral performance and could serve as the basis for further characterization in the large number of Egyptian athletes.