Catechol-O-Methyltransferase (COMT) Genotype, Varies

Casandra

Casandra Test Code MC83319Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID COMTQCPT Code 0032

Catechol-O-Methyltransferase (COMT) Genotype, Varies

Clinical Use

Use

The COMT Genotype test is useful for predicting the response to nicotine replacement therapy for smoking cessation and investigating dosing strategies to reduce levodopa metabolism in Parkinson's disease therapy. It is also applied in research settings to assess estrogen metabolism. COMT is involved in the phase II metabolism of catecholamines, catechol drugs such as dopamine, and catechol-estrogens. COMT transfers a methyl group to catechol structures, impacting metabolites like normetanephrine, metanephrine, and homovanillic acid.

Special Instructions

The test should not be ordered for pheochromocytoma or paraganglioma assessment. Instead, order other specific tests such as METAF or PMET. For genotype testing related to psychotropic medications, the Psychotropic Pharmacogenomics Gene Panel should be considered. Specimens from patients who have undergone blood transfusions or allogeneic hematopoietic stem cell transplantation may not produce accurate genotype results.

Limitations

This test detects the Val108/158Met single nucleotide variant in exon 4 of the COMT gene, which significantly reduces enzyme activity compared to the wild type. The absence of a detectable variant does not rule out an intermediate or poor metabolizer phenotype. Variants in primer binding regions may affect results, as could donor DNA from blood transfusions or transplants. The enzyme activity can be influenced by medication and dietary factors that interact with COMT.

Test Details

New York Approved