TARDBP and amyotrophic lateral sclerosis: Rare mutations in the related heterogeneous nuclear ribonucleoproteins hnRNPA1 and hnRNPA2B1 have also been reported in a small subset of patients with ALS as well as a rare disorder termed multisystemic proteinopathy (MSP) – which is characterized by progressive degeneration of muscle, brain, motor neurons and bone, in combination with pronounced TDP-43 pathology [47].