Genetic polymorphisms in monoamine neurotransmitter systems show only weak association with acute post-surgical pain in humans.
BACKGROUND
Candidate gene studies on the basis of biological hypotheses have been a practical approach to identify relevant genetic variation in complex traits. Based on previous reports and the roles in pain pathways, we have examined the effects of variations of loci in the genes of monoamine neurotransmitter systems including metabolizing enzymes, receptors and transporters on acute clinical pain responses in humans.


RESULTS
Variations in the catecholamine metabolizing enzyme genes (MAOA and COMT) showed significant associations with the maximum post-operative pain rating while the serotonin transporter gene (SLC6A4) showed association with the onset time of post-operative pain. Analgesic onset time after medication was significantly associated with the norepinephrine transporter gene (SLC6A2). However, the association between COMT genetic variation and pain sensitivity in our study differ from previous studies with small sample sizes, population stratification and pain phenotype derived from combining different types of pain stimuli. Correcting for multiple comparisons did not sustain these genetic associations between monoamine neurotransmitter systems and pain sensitivity even in this large and homogeneous sample.


CONCLUSIONS
These results suggest that the previously reported associations between genetic polymorphisms in the monoamine neurotransmitter systems and the interindividual variability in pain responses cannot be replicated in a clinically relevant pain phenotype.
Kim
Hyungsuk
H
National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA. kimhy@mail.nih.gov
Lee
Hyewon
H
Rowan
Janet
J
Brahim
Jaime
J
Dionne
Raymond A
RA
D000208:Acute Disease; D015306:Biogenic Monoamines / Q000378:metabolism*; D001923:Brain Chemistry / Q000235:genetics*; D002394:Catechol O-Methyltransferase / Q000235:genetics; D002395:Catecholamines / Q000378:metabolism; D002490:Central Nervous System / Q000378:metabolism* / Q000503:physiopathology; D004252:DNA Mutational Analysis; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D006801:Humans; D008297:Male; D008995:Monoamine Oxidase / Q000235:genetics; D018377:Neurotransmitter Agents / Q000378:metabolism; D050484:Norepinephrine Plasma Membrane Transport Proteins / Q000235:genetics; D017288:Pain Threshold; D010149:Postoperative Pain / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D011110:Polymorphism, Genetic / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012701:Serotonin / Q000378:metabolism; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics
D015306:Biogenic Monoamines; D002395:Catecholamines; D018377:Neurotransmitter Agents; D050484:Norepinephrine Plasma Membrane Transport Proteins; D050486:Serotonin Plasma Membrane Transport Proteins; D012701:Serotonin; D008995:Monoamine Oxidase; D002394:Catechol O-Methyltransferase