FIG4 and amyotrophic lateral sclerosis: For 9 patients carrying Class-4 and Class-5 gene variants, the molecular findings supported a probable diagnosis of genetic ALS: two were subjects carrying different heterozygous Class-5 missense variants in OPTN, two subjects had different pathogenic Class-5 variants in VCP gene, one patient was compound heterozygous for a Class-4 and a Class-5 FIG4 variant (P100), two subjects carried a Class-4 missense variant and a splicing variant in SQSTM1 (P002, and P103), and one subject carried a Class-4 heterozygous GARS1 gene variant (c.1955G>A; p.Gly652Glu, P073) (Table 4).