Of note, missense mutations in AFG3L2/OPA12 are also known to cause the unrelated disorders spinocerebellar ataxia type 28 (SCA28) and spastic ataxia syndrome 5 (SPAX5) but these mutations are generally localized within the proteolytic domain of the protein (Caporali et al., 2020). This evidence concerns the gene AFG3L2 and spinocerebellar ataxia type 28.