A novel point mutation in the mitochondrial tRNA(Trp) gene produces a neurogastrointestinal syndrome

We report a novel, heteroplasmic point mutation in the mitochondrial tRNA for tryptophan at position 5532. The mutation was present in all the tissues studied and segregated with the biochemical defect, with higher levels of mutation present in cytochrome c oxidase-deficient muscle fibres. The patient manifested a neurogastrointestinal syndrome with features including failure to thrive, psychomotor retardation, ophthalmoplegia, sensorineural deafness and encephalopathy together with vomiting, diarrhoea and colitis.