SENSORY ATAXIC NEUROPATHY AS THE PRESENTING FEATURE OF A NOVEL MITOCHONDRIAL DISEASE

Four unrelated patients presented with a severe sensory ataxic neuropa thy in association with dysarthria and chronic progressive external op hthalmoplegia. Electrophysiologic and pathologic studies showed severe axonal loss disproportionately affecting sensory nerves. Molecular ge netic analysis revealed multiple mitochondrial DNA deletions in muscle and peripheral nerve. Sensory ataxic neuropathy may be the predominan t and presenting manifestation of a mitochondrial disorder, and a mito chondrial etiology should be included in its differential diagnosis. T he triad of sensory ataxic neuropathy, dysarthria, and ophthalmoparesi s (SANDO) may represent a novel mitochondrial disease associated with multiple mitochondrial DNA deletions.