SORD and Charcot-Marie-Tooth disease type 2: Despite the relatively high frequency of the heterozygous c.757delG (p. A253Qfs*27) variant, the reason why SORD had not been previously identified as a causative gene for recessive CMT2 or dHMNs may be partly due to the presence of the pseudogene, which is a highly homologous, but nonfunctional, paralog of SORD (4).