The paper presents the description of Duchenne progressive muscular dystrophyin an 18-month-old and an 8-year-old boy. The diagnosis was established on the basis of clinical symptoms,such as impaired motor development, hypertrophy of leg muscles, difficulty in walking; elevated serumphosphocreatine kinase activity and pathologic electromyographic recordings. The authors emphasize thatthe disease is characterized by increased activity of such enzymes as: alanine and aspartate aminotransferases,lactate dehydrogenase and aldolase--observed as early as in the first weeks of life, with normal gammaglutamyltranspeptidaseactivity suggests progressive muscular dystrophy and makes it possible to establish early diagnosis.Early diagnosis of the disease allows to start rehabilitation earlier, to select an appropriate typeof anesthesia in case of surgical treatment and to advise parents within the framework of genetic counseling.

Keywords: Alanine Transaminase, Alkaline Phosphatase, Aspartate Aminotransferases, Child, creatine kinase, Hypertrophy, Isoenzymes, L-Lactate Dehydrogenase, Motor Activity, Muscle, Skeletal, Muscular Dystrophy, Duchenne, Walking, gamma-Glutamyltransferase