The importance of multiple gene analysis for diagnosis and differential diagnosis in charcot marie tooth disease

Aim Charcot-Marie-Tooth (CMT) disease or hereditary motor and sensory neuropathy (HMSN) is the definition of a genetically heterogeneous group of diseases characterized by the impaired function of peripheral nerves. The aim of this study was to investigate the genetic etiology of CMT. Material and methods We herein examined 55 non-related patients with a suspicion of CMT phenotype or HMSN using a customized multigene panel based on the next-generation sequencing technique. All cases were previously analyzed for PMP22 duplication with the Multiplex Ligand Probe Amplification (MLPA) method. Results In 13 cases (7.15%), we identified a pathogenic/likely pathogenic variants. The affected genes were MARS1, NDRG1, GJB1, GDAP1, MFN2, PRX, SH3TC2, and FGD4. In six cases (10.9%), novel variants were identified: pathogenic variants in GJB1 and FGD4 genes, variants of unknown significance (VUS) in HSPB3, CHRNA1, ARHGEF10, and KIF5A genes. In 21 cases (11.55%), VUS with the genes HSPB3, KIF1B, SCN11A, CHRNA1, HSPB1, FIG4, ARHGEF10, DHTKD1, SBF1, EGR2, SBF2, IGHMBP2, KIF5A, and DNAJB2 were identified. Conclusion In this study, we had a 7.15% diagnosis rate with the NGS (Next Generation Sequencing) method in the CMT disease. Targeted next-generation sequencing panels are beneficial, time-saving, and cost-effective in the diagnosis of CMT.