Trigeminal Neuralgia Trpm8 Mutation

ObjectiveTo assess the functional effects of a variant, c.89 G > A (p.Arg30Gln), in the transient receptor potential melastatin 8 (TRPM8) cold-sensing, nonselective cation channel, which we have previously identified in a patient with familial trigeminal neuralgia.MethodsWe carried out Ca2+ imaging and whole-cell patch-clamp recording.ResultsThe TRPM8 mutation enhances channel activation, increases basal current amplitude and intracellular [Ca2+] in cells carrying the mutant channel, and enhances the response to menthol.ConclusionsWe propose that Arg30Gln confers gain-of-function attributes on TRPM8, which contribute to pathogenesis of trigeminal neuralgia in patients carrying this mutation.