Autosomal dominant optic atrophy (ADOA, Kjer disease, MIM #165500) is the most common form of hereditary optic neuropathy. Mutations in OPA1 located at chromosome 3q28 are the predominant cause for ADOA explaining between 32 and 89% of cases. Although deletions of OPA1 were recently reported in ADOA, the frequency of OPA1 genomic rearrangements in Denmark, where ADOA has a high prevalence, is unknown. The aim of the study was to identify copy number variations in OPA1 in Danish ADOA patients.