Full Name: Catechol-O-Methyltransferase

Genomic Location: Chromosome 22:19,941,607-19,969,975

Protein Size: 271 amino acids


Catalyzes the O-methylation, and thereby the inactivation, of catecholamine neurotransmitters and catechol hormones. Also shortens the biological half-lives of certain neuroactive drugs, like L-DOPA, alpha-methyl DOPA and isoproterenol.

Catechol-O-methyltransferase catalyzes the transfer of a methyl group from S-adenosylmethionine to catecholamines, including the neurotransmitters dopamine, epinephrine, and norepinephrine. This O-methylation results in one of the major degradative pathways of the catecholamine transmitters. In addition to its role in the metabolism of endogenous substances, COMT is important in the metabolism of catechol drugs used in the treatment of hypertension, asthma, and Parkinson disease. COMT is found in two forms in tissues, a soluble form (S-COMT) and a membrane-bound form (MB-COMT). The differences between S-COMT and MB-COMT reside within the N-termini.

Linked SNP(s):

  • rs5128 is linked to COMT, it is located in the protein coding region of the gene.
  • Population frequencies are approximately 54% for the reference allele (G) and 46% for the alternate allele (A).
  • Studies suggest the G allele is associated with increased emotional processing, while the A allele is associated with increased cognition and impulsivity. 
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