Trigeminal Neuralgia in MPZ Gene-related Families: A Family Report and Literature Review

Background: Trigeminal neuralgia (TN) is one of the most common clinical cranial nerve disorders. Typical TN is characterized by paroxysmal severe pain, which can be described as electric shock-like, needle-prick-like, or tearing-like. Each episode lasts from several seconds to several minutes, seriously impairing patients' quality of life, work ability, and social interaction skills. A family with 2 or more patients suffering from trigeminal neuralgia is defined as a familial trigeminal neuralgia (FTN，Familial trigeminal neuralgia) family. Currently, research on FTN remains relatively scarce. Objective: To enhance clinicians' understanding of the relationship between trigeminal neuralgia and genetics, facilitate early screening and identification of suspected FTN patients, provide insights into the pathogenesis of FTN, and offer references for the treatment and prognosis of affected patients. Methods: Whole-genome sequencing and Sanger sequencing of the single locus in the myelin protein zero (MPZ) gene were performed on 5 members of a TN family (including 3 TN patients and 4 individuals with scoliosis and pes cavus). Results: All 4 tested family members carried a heterozygous mutation at the c.308G>A (p.Gly103Glu) locus, which was inherited from the proband's mother. Sanger sequencing of the single MPZ locus in the proband's father showed no variation. The 3 TN patients underwent treatments such as microvascular decompression of the trigeminal nerve or percutaneous balloon compression of the trigeminal ganglion, with favorable postoperative outcomes and no pain recurrence. Conclusion: Through whole-genome sequencing and literature review, our team identified a novel variant-MPZ c.308G>A (p.Gly103Glu)-that is associated with FTN, a rarely reported phenotype. Additionally, members of this family exhibited clinical manifestations of Charcot-Marie-Tooth disease (CMT), such as scoliosis and pes cavus.