Nonsynonimous mutation of catechol-O-methyl-transferase (COMT) gene in a patient with temporomandibular disorder.

We report a case of temporomandibular disorder patient with disc displacement without reduction, myofascial pain, limited opening and a novel, never described, nonsynonimous mutation of catechol-O-methyl-transferase (COMT) gene. COMT is one of the enzymes that metabolizes catecholamines, thereby acting as a key modulator of dopaminergic and adrenergic/noradrenergic neurotransmissions, which play a key role in pain modulation. This novel mutation, p.R58S, changed a codon (58 from arginine to serine) in the COMT protein. The introduction of a serine residue in a highly organised secondary structure, in critical regions of the protein, results in a structural alteration. Therefore, we speculate an influence of the mutation on the high pain sensitivity of the patient.