Trigeminal neuralgia, demyelinating polyneuropathy, and central nervous system involvement in a patient with an SH3TC2 mutation

Abstract

Abstract Background Charcot-Marie-Tooth type 4C (CMT4C) is a slowly progressive, autosomal recessive, sensorimotor polyneuropathy characterized by demyelination and distinct clinical features, including cranial nerve involvement. CMT4C is associated with pathogenic mutations in the SH3TC2 gene. Methods A patient presenting with gait instability due to demyelinating polyneuropathy and refractory trigeminal neuralgia underwent comprehensive evaluation. Nerve conduction studies, magnetic resonance imaging (MRI) of the brain, cervical spine, and thoracic spine, lumbar puncture, and genetic test through next generation sequencing were performed. Results The genetic test found an Arg1109Stop mutation in the SH3TC2 gene, associated with demyelinating polyneuropathy and cranial neuropathy. Interestingly, brain MRI showed multiple, nonenhancing white matter hyperintensities. This is the first case of CMT4C associated with white matter lesions. Conclusion Any patient with slowly progressive peripheral nervous system symptoms and disproportionally abnormal nerve conduction study findings should be tested for an inherited polyneuropathy and brain imaging for screening of possible central nervous system involvement should be performed. Further investigation is needed to elucidate the pathogenetic basis of CMT4C and a possible association with white matter lesions.