A novel point mutation in the mitochondrial tRNA(TrP) gene produces late-onset encephalomyopathy, plus additional features

Background: Mitochondrial diseases due to mitochondrial tRNA genes mutations are usually multisystem disorders with infantile or adult onset. Objective: To identify the molecular defect underlying a mitochondrial encephalomyopathy. Methods/Patients: Case report of a 51 year-old woman presenting with late-onset myoclonic epilepsy plus additional features. Proband's mother presented hypothyroidism and diabetes. Results: Muscle biopsy showed mitochondrial changes. Respiratory chain activities were reduced. The novel G5538A mutation was identified in different tissues DNAs from the proband and from her mother. Conclusion: We were able to identify a novel mtDNA tRNA((TrP)) gene pathogenic mutation. (C) 2010 Elsevier B.V. All rights reserved.