An Apparently Isolated Optic Neuropathy Associated with Biallelic Variants in SLC25A46 Gene Encoding the...

Biallelic pathogenic variants in the SLC25A46 gene are responsible for various neurological syndromes, including Charcot-Marie-Tooth disease type 6B, pontocerebellar hypoplasia type 1E, Leigh syndrome, progressive myoclonic ataxia and Parkinson's disease, most of them being associated with optic atrophy. We here report the case of a 26-year-old female patient with a slowly progressive and apparently isolated form of optic neuropathy due to the NM_138773.4:c.[327-2A > T];[410A > G] compound heterozygous variants in this gene. The presence of a subclinical peripheral neuropathy revealed by electroneuromyography confirmed the responsibility of these SLC25A46 variants. The absence of functional and structural mitochondrial abnormalities in the patient's fibroblasts was consistent with the mild neurological phenotype. This case report suggests that SLC25A46 gene merit consideration during genetic testing for both syndromic and isolated optic neuropathies.