It has been reported that the 3460/ND1 mutation, when associated with specific cytochrome b (cytb) variants, specifically 15773/cytb alone or in combination with 15693/cytb, may contribute to the clinical expression of a syndromic form of optic atrophy referred to as LHON ‘plus.’9 This syndromic form may include variable central nervous system (CNS) involvement such as lesions of the basal ganglia, a Leigh-like syndrome, cerebellar atrophy, migraine, epilepsy and peripheral neuropathy,1 cardiac involvement with conduction abnormalities,10 skeletal deformities11 and myoclonus.9–12. This evidence concerns the gene MT-CYB and Myoclonus.