Longitudinal 16-year study of dominant intermediate CMT type C neuropathy

Background: Dominant-intermediate Charcot–Marie-Tooth neuropathy subtype C (DI-CMTC) is associated with mutations in the YARS gene. The aim of this study is to investigate the long-term natural history of the disease. Methods: In a 5-generation DI-CMTC family, we compared data from 2016 to that of 2000 in 13 of 21 original participants. Results: Five women and 8 men were examined. While most symptoms and signs progressed, only gait progression was statistically significant (P =.016). The median CMT Neuropathy Score was 6.08 in 2000 and 11 in 2016 (P =.001). Quality of life (QOL) deteriorated in mobility (P =.008), pain/discomfort (P =.011), and anxiety/depression (P =.014). Median and ulnar compound muscle action potential amplitudes decreased from 9.35 ± 2.90 mV to 6.0 ± 2.9 mV (P =.002), and from 9.24 ± 2.10 mV to 6.06 ± 1.81 mV (P =.004), respectively, whereas motor nerve conduction velocities remained unchanged. Conclusions: DI-CMTC in this family is a slowly progressive disease with axonal degeneration, deteriorating mobility and QOL.