FIG4 and Charcot-Marie-Tooth disease type 4J: It is also known that ALS shares genetic characteristics with other complex diseases, including Charcot-Marie-Tooth (CMT4J); namely, mutations in FIG4, a phosphatase that regulates intracellular vesicle trafficking along the endosomal-lysosomal pathway, have been associated with both diseases (Kon et al., 2014).