AFG3L2 and spastic ataxia 5: AFG3L2 mutations cause three monogenic disorders which are spinocerebellar ataxia type 28 (SCA28), spastic ataxia type 5 (SPAX5), and optic atrophy type 12 (OPA12) and have been reported for their mechanistic association with other diseases such as PD and other eye associated ataxias like ophthalmoparesis and oculomotor apraxia [9].