Autosomal recessive spastic paraplegia type 55

Autosomal recessive spastic paraplegia type 55 (SPG 55) is a rare, complex type of hereditary spastic paraplegia characterized by childhood onset of progressive spastic paraplegia associated with optic atrophy (with reduced visual acuity and central scotoma), ophthalmoplegia, reduced upper-extremity strength and dexterity, muscular atrophy in the lower extremities, and sensorimotor neuropathy. SPG55 is caused by mutations in the <i>C12ORF65</i> gene (12q24.31) encoding probable peptide chain release factor C12orf65, mitochondrial.