The association of monoamine oxidase B functional polymorphism with postoperative pain intensity.

OBJECTIVES: The monoamine oxidase B (MAO-B) is an enzyme involved in metabolism of dopamine, benzylamine, phenylethylamine, tyramine and tryptamine. The A/G polymorphism in intron 13 of the MAO-B gene has been previously found to be associated with variability of the MAO-B enzyme activity. The aim of the present association study has been to examine the relationship between the A/G polymorphism in intron 13 and postoperative pain intensity. METHODS: 284 subjects (105 males and 179 females) undergoing planned tonsillectomy were examined. The intensity of pain was evaluated using 100-mm visual analogue scale (VAS). A PCR method with allele specific primers for detection of A/G polymorphism was used. RESULTS: We found a relationship between the A/G polymorphism in intron 13 of the MAO-B gene and average intensity of postoperative pain in male subjects. Higher average intensity of postoperative pain was detected in males with the G allele (3.96) in comparison with males with the A allele (3.45) and the difference was statistically significant (p<0,03). CONCLUSIONS: Results of this study indicate the relationship between the MAO-B polymorphism and postoperative pain intensity in the Czech male population. A potential role of MAO-B in the perception of pain intensity is discussed.

The association between high-activity COMT allele and alcoholism.

OBJECTIVES: The catechol-O-methyltransferase (COMT) is an enzyme involved in the metabolism of dopamine, adrenaline and noradrenaline. The Val158Met polymorphism of the COMT gene has been previously associated with a variability of the COMT activity, and alcoholism. The aim of the present association study was to examine the relationship between the Val158Met polymorphism of the COMT gene and dispositions to alcoholism. METHODS: In our case control study we analyzed DNA samples from 799 subjects in total (279 male alcoholics and 120 female alcoholics, 151 male controls and 249 female controls). The restriction analysis for the detection of the Val158Met polymorphism was used. RESULTS: We found a relationship between the Val158Met polymorphism of the COMT gene and alcoholism in male subjects. We found the significant difference between male alcoholics and male controls in allele and genotype frequencies (p<0,007; and p<0,04 respectively). CONCLUSIONS: Our study confirmed the relationship between the COMT polymorphism and alcoholism in the Czech male population.

Polymorphism of DRD2 gene and ADHD.

OBJECTIVES: Attention deficit hyperactivity disorder (ADHD) is a prevalent childhood disorder. Evidence from the family and twin studies suggest that ADHD is familiar and highly heritable. Association studies are frequently used for the searching of markers responsible for genetic basis of ADHD. We investigated TaqI polymorphism of the dopamine receptor D2 (DRD2) in relationship with ADHD. The association between TaqI A polymorphism of DRD2 gene and ADHD has previously been published. DESIGN: We used the association study to test the relationship between TaqI A polymorphism of DRD2 gene and ADHD on groups of ADHD boys and control boys. SETTING: For DNA isolation, buccal tissue was used. PCR with restriction analysis of PCR products was used for genotyping. RESULTS: We found statistically different genotypic and allelic frequencies (p < 0.008, p < 0.002, respectively) of DRD2 polymorphism between two studied groups of boys. MAIN FINDINGS: According to our results we suppose that polymorphism TaqI A of DRD2 gene is involved in the pathogenesis of childhood ADHD in male subjects. Allele A1 and genotype A1A1 in male subjects is associated with ADHD. CONCLUSIONS: Our study confirmed the relationship between TaqI A polymorphism of DRD2 gene and ADHD published previously.