Haploinsufficiency is a disease mechanism shared by different ALS-related genes, such as TBK1 and DNAJC7.[43, 51] A recent study reported a variant leading to small ubiquitin-like modifier (SUMO4) haploinsufficiency as a novel potential genetic risk factor for ALS. The gene discussed is DNAJC7; the disease is amyotrophic lateral sclerosis.