RTN4IP1 and Leber hereditary optic neuropathy: Following the first reported association of bi-allelic, pathogenic RTN4IP1 gene variants with either isolated optic atrophy or a multisystem neurological disease presentation with optic nerve involvement (Angebault et al, 2015), (OMIM:610502), targeted and whole exome sequencing approaches have been used to identify further disease-causing variants and establish a genotype-phenotype correlation (Angebault et al, 2015; Aldosary et al, 2022; Charif et al, 2018).