mitochondrial DNA depletion syndrome AFG3L2-related optic atrophy and/or spastic ataxia spectrum https://github.com/monarch-initiative/mondo/issues/7826 GARD:0028028 Any disorder caused by a heterozygous variant or biallelic variants in the AFG3L2 gene and characterized by a spectrum of phenotypes including optic atrophy and/or spastic ataxia. AFG3L2-related optic atrophy and/or spastic ataxia spectrum MONDO:0700372