Here, we report the results of a comprehensive study on OPA3 mutations, including the mutation spectrum and its prevalence in a large cohort of OPA1-negative autosomal dominant optic atrophy (ADOA) patients, the associated clinical phenotype and the functional characterisation of a newly identified OPA3 mutant.
Dominant optic atrophy (DOA) is genetically heterogeneous and pathogenic mutations have been identified in the OPA1 and OPA3 genes, both encoding for mitochondrial proteins.
Autosomal-dominant optic atrophy (DOA) is one of the most common inherited optic neuropathies, and it is genetically heterogeneous, with mutations in both OPA1 and OPA3 known to cause disease.
All the patients were investigated for Leber's hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (ADOA), by searching for the ten primary LHON-causing mtDNA mutations and examining the entire coding sequences of the OPA1 and OPA3 genes, the two genes currently identified in ADOA.
We found a common coupling defect of oxidative phosphorylation in fibroblasts of patients affected by autosomal dominant optic atrophy (mutations of OPA1), autosomal dominant optic atrophy associated with cataract (mutations of OPA3), and Leber's hereditary optic neuropathy, a disorder associated with point mutations of mitochondrial DNA complex I genes.