LEBER-FELE HEREDITAER OPTICUSNEUROPATHIA - VIRUSROMALST OKOZO MITOCHONDRIALIS DNA-MUTACIO

Introduction - Several human diseases are caused by mitochondrial DNA mutations and the information on them has been markedly increased in the last few years. Many important respiratory chain enzymes are mitochondrially encoded, so the first symptoms usually involve the organs with high respiratory function - for example brain and muscle. In this study clinical and electrophysiological data of genetically diagnosed LHON (Leber's hereditary optic neuropathy) patients are presented in order to evaluate the clinical manifestation of the disease and its statistical features (serrate, age at onset, phenotype manifestation rate). Patients and Methods - Peripheral venous blood of patients with bilateral optic neuropathy was tested for the pathogenic LHON point mutations. The LHON positive family members were examined clinically and electrophysiologically. Results -The clinical symptoms and statistical features (sex rate, disease onset, rate of phenotype manifestation etc) of LHON positive patients in this study were similar to those of other caucasian cohorts. The visual evoked potential test showed that bilateral optic nerve lesion is a combined axonal-demyelinating type. On electromyography mild axonal lesion was found in 37% of the patients. Conclusion - In the differential diagnosis of bilateral optic neuropathies pathogenic LHON mutations play an important role. The exact genetic diagnosis of LHON and other mitochondrial diseases could help to predict the prognosis of the disease and to protect the patients from the damaging side-effects of ineffective therapies.