This observation was consistent with the reduced OPA1 protein levels observed in another patient (NO-1) with a complicated syndromic DOA phenotype characterised by optic atrophy and marked generalised neurodegenerative features, who has been confirmed to harbour compound heterozygous OPA1 missense mutations in exon 5b (c.768C>G, p.Ser256Arg) and exon 8 (c.854A>G, p.Gln285Arg; figure 1C). Here, OPA1 is linked to hereditary optic atrophy.