Wellcome to healthcaremagic Duchenne muscular dystrophy (DMD) is a recessive X-linked form of muscular dystrophy, affecting around 1 in 3,600 boys, which results in muscle degeneration and eventual death. The disorder is caused by a mutation in the dystrophin gene, the largest gene located on the human X chromosome, which codes for the protein dystrophin, an important structural component within muscle tissue that provides structural stability to the dystroglycan complex (DGC) of the cell membrane. While both sexes can carry the mutation, females rarely exhibit signs of the disease. Symptoms usually appear in male children before age 6 and may be visible in early infancy. Following tests are performed to diagnose DMD DNA test -DNA testing and analysis can usually identify the specific type of mutation of the exon or exons that are affected. DNA testing confirms the diagnosis in most cases. Muscle biopsy -If DNA testing fails to find the mutation, a muscle biopsy test may be performed. A small sample of muscle tissue is extracted (usually with a scalpel instead of a needle) and a dye is applied that reveals the presence of dystrophin. Complete absence of the protein indicates the condition. The mutation in the dystrophin gene could be because of any of the following: 1.deletions (missing parts) 2.duplications (additional parts) 3.point mutations (changed parts)