MAPT and X-linked retinal dysplasia: Therefore, these diseases are often described as protein misfolding disorders (PMDs), which are caused by the accumulation of specific misfolded proteins: amyloid-β (Aβ) and tau in AD; α-synuclein, ubiquitin, and tau in PD; TAR DNA-binding protein 43 (TDP-43) and superoxide dismutase 1 (SOD-1) in ALS; huntingtin protein in HD; prion protein in PrD; rhodopsin in RP; and myelin in demyelinating disorders [27,147,148,149,150].