MT-ND5 gene mutation-associated mitochondrial complex I cytopathy in Leigh syndrome presenting as writer’s cramp: A case report

Leigh syndrome is a classical mitochondrial cytopathy with multisystemic presentation that can lead to death in the first few years of life; however, cases in adults have also been reported. In this study, we report the case of an adolescent female presenting with writer’s cramp associated with the MT-ND5 gene mutation, diagnosed after observation of brain abnormalities on magnetic resonance imaging (MRI) and biochemical changes suggestive of mitochondrial cytopathy. The patient responded to botulinum toxin injection. To the best of our knowledge, ours is the first case report on focal dystonic presentation associated with the MT-ND5 gene mutation (with unclear pathogenicity) as a mild form of Leigh syndrome in adolescents.