Trigeminal Neuralgia TRPM8 Mutation: Enhanced Activation, Basal [Ca2+]i and Menthol Response

Neurol Genet. 2021 Jan 11;7(1):e550. doi: 10.1212/NXG.0000000000000550. eCollection 2021 Feb.

Abstract

Objective: To 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.

Methods: We carried out Ca2+ imaging and whole-cell patch-clamp recording.

Results: The TRPM8 mutation enhances channel activation, increases basal current amplitude and intracellular [Ca2+] in cells carrying the mutant channel, and enhances the response to menthol.

Conclusions: We propose that Arg30Gln confers gain-of-function attributes on TRPM8, which contribute to pathogenesis of trigeminal neuralgia in patients carrying this mutation.