[Deletions of the mitochondrial DNA associated to chronic progressive external ophthalmoplegia with ragged-red fibers in 2 Brazilian patients].

BACKGROUND AND

OBJECTIVE

Our purpose was to report the neurological manifestations and molecular-genetic analysis of mitochondrial DNA associated with chronic progressive external ophthalmoplegia (CPEO) and raged red fibers (RRFs).

PATIENTS AND METHOD: Two patients, a male and a female (32 and 28 year-old, respectively), were studied due to progressive palpebral ptosis associated with RRFs in muscle biopsy. Both patients were subjected to neurological, histochemical and enzymatic analysis of muscular biopsy, analysis of cerebro-spinal fluid, and molecular analysis of mitochondrial DNA.

RESULTS

Symptoms started at ages 24 and 17 years. Initial symptoms were palpebral ptosis, progressive limitation of vertical and horizontal gaze, fatigue and exercise intolerance, and weakness of proximal muscles. Brain MRIs were normal in both patients. Both patients had deletions of muscle mitochondrial DNA with similar size (5,425 and 5,112 base pairs) and location.

CONCLUSIONS

CPEO with RRFs is usually associated with huge deletions in mitochondrial DNA. Fatigue and proximal muscle weakness can be found during the follow-up.