Abstract
A 55-year-old male presented with apraxia of gait with exaggerated upper limb movement with relative preservation of cognition and mild spasticity of limbs. His investigations reveal posterior-predominant leukodystrophy in brain magnetic resonance imaging (MRI) and compound heterozygous mutations in mitochondrial alanyl-transfer RNA synthetase 2 (AARS2) by next generation sequencing. His asymptomatic brother also has MRI changes with subtle mild pyramidal signs. AARS2 mutation is a rare cause of mitochondrial encephalopathy which may give rise to leukodystrophy with premature ovarian failure, infantile cardiomyopathy, lung hypoplasia and myopathy. Gait apraxia as primary presenting feature of this rare variant of mitochondrial encephalomyopathy is hitherto un-reported.