Ocular abnormalities, such as pigmentary retinal degeneration, ophthalmoplegia, optic atrophy, cataracts, and nystagmus, are common in other forms of spastic paraplegia, such as SPG7 (MIM: 607259), SPG35 (MIM: 612319), or SPG45 (MIM: 613162), not linked to AP5Z1, where ophthalmic changes may precede extra-ocular motor symptoms.71 The gene discussed is NT5C2; the disease is Nystagmus.