Hello, I suspect that he is suffering from Muscular Dystrophy. Muscular dystrophy (MD) is a genetic disorder that weakens the muscles that help the body move. People with Muscular Dystrophy have incorrect or missing information in their genes, which prevents them from making the proteins they need for healthy muscles. Because Muscular Dystrophy is genetic, people are born with the problem. Muscular Dystrophy weakens muscles over time, so children, teens, and adults who have the disease can gradually lose the ability to do the things most people take for granted, like walking or sitting up. Someone with MD might start having muscle problems as a baby or their symptoms might start later. Some people even develop MD as adults. He may be suffering from either Duchenne or Becker s muscular dystrophy. Because are common and very common in boys. In Beckers dystrophy , the symptoms appear later and is not severe than Duchenne s. In addition to creatine kinase, he need following investigations. 1. Muscle biopsy - this involves taking a small sample of muscle under local anaesthetic. The sample is examined under the microscope and the muscle chemicals (proteins) may be tested. 2. Genetic analysis - this involves testing a person s DNA using a blood sample. It can detect many (not all) cases of Muscular Dystrophy. 3. An electromyogram (EMG) - this is a recording of the electrical activity in a muscle. 4. Muscle ultrasound is used to look for suspected Muscular Dystrophy. There is no cure for Muscular Dystrophy, although there are treatments which can help. The treatment offered will depend on what type of Muscular Dystrophy your child have. Physiotherapy, steroids and splints are available treatment options now. Hope this helps. Please write back for further queries. Wishing you good health.