Conventional EMG and Quantitative EMG( Quantitative MUAP analysis, SFEMG and Macro EMG) were carried out for 20 control subjects, 40 myopathic patients and 16 of their siblings. Those techniques were of high diagnostic value in the early detection of myopathic changes in patients and their siblings. The QEMG parameters were correlated with the clinical data. Muscle biopsy was carried out for 19 patients,it was correlated to the clinical and QEMG Findings and was diagnostic in all patients.