We studied a 62 year-old woman with a clinical phenotype characterized by encephalopathy, restrictive cardiomyopathy, and prominent intestinal pseudo-obstruction. Muscle morphology showed ragged red fibres with ultrastructurally abnormal mitochondrial whereas muscle respiratory chain was normal. Molecular genetics revealed the 'common deletion' in mtDNA, which represented 40% of total mtDNA. These data expand and confirm the wide clinical spectrum of mitochondrial disorders associated with single large-scale mtDNA deletions.