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 51year-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.