Abstracts

Rationale: MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke like episodes) is a maternally inherited multisystem mitochondrial disorder, with neuropsychiatric involvement as one of the most common clinical manifestations. Seizures -partial or generalized seizures and frequently status epilepticus- can be the initial presentation in these patients. We report a case of a patient with the clinical presentation of MELAS where the testing of the common genetic causes was negative. Methods: Single case study Results: A 24-year-old male patient with short stature presented initially with seizures, hearing loss and fluctuating impaired vision. He suffered from partial onset seizures, complex partial seizures and generalized seizures. The treatment with levetiracetam lead to an aggravation of his depressive adaptation disorder therefore lamotrigin was prescribed successfully. During the time he additionally developed recurrent headaches and ataxia. The brain MRI revealed marked cortical/subcortical parieto-occipital stroke-like lesions that did not follow vascular territories. Cerebrospinal fluid (CSF) examination showed protein mildly raised, normal glucose and elevates lactate (54.1 mg/dl). To confirm our suspected diagnosis of MELAS we tested for the most common known mutations (3243A>G and 3271T>C) and screend the whole transfer RNA but no mutation was dedected. In the muscle biopsy specimen of the patient no ragged red fibers were found. In the extensive work up of the mitochondrial DNA (mtDNA) in the muscle biopsy we found in one of the 7 subunits of Complex I the G13513A mutation in nicotinamide adenine dinucleotide (NADH) dehydrogenase 5 (ND5) gene prediscrebed in cases of MELAS and Leigh Syndrome. Conclusions: The G13513A mutation should be considered as a potential cause of MELAS, especially if ragged-red fibers are negative.