Neuropathy, Hereditary Motor, and Sensory Types VIA and VIB

The heterogeneity of hereditary motor sensory neuropathy (HMSN), commonly known as Charcot-Marie-Toth disease, is so vast and Dyck’s classification from 1975 includes seven different types (Kumar et al. n.d.). This chapter focuses on HMSN VI A and VI B, two medical conditions characterized by peripheral polyneuropathy and optic atrophy (Voo et al. 2003). Recent observations of differences in inheritance patterns suggest that multiple genes are involved in HMSN VI. It has been divided into three subgroups: HMSN VI A, HMSN VI B, and HMSN VI C (Chelban et al. 2019). Pathogenic variants of mitofusin2 (MFN2) are responsible for HMSN VI A (Babu et al. 2022), and pathologic variants of the SLC25A46 gene are associated with HMSN VI B (Hammer et al. 2017).