Duchenne muscular dystrophy is a rare and genetic disease characterized by progressive muscle weakness and degeneration/ loss (atrophy) of skeletal and cardiac muscles.
The underlying cause of DMD are mutations in the DMD gene which result in the absence of the protein dystrophin, an essential element to keep the muscle cells intact. The dystrophin protein is responsible for transferring the force of the muscle cell contraction from the centre to the muscle cell periphery.
Boys are primarily affected by this disease. The symptoms onset occurs in early childhood, usually between the ages 3 and 5. This is characterized by the delayed ability to sit, stand or walk. Muscle weakness appear beginning with the age of 3, firstly affecting the muscles of the hips, pelvic area, thighs and shoulders, and later the situation worsens progressing to the skeletal muscles of arms, legs and trunk. Children affected by this disorder will have difficulties in running, jumping, climbing stairs and getting up from the floor. DMD may further affect learning, memory as well as communication and social and emotional skills. At early teenage, the heart and respiratory muscles get affected as well, leading to life-threatening complications, hence representing the main cause of death. There is no cure for DMD, however treatments are available that help to control the symptoms. For this reason, investigations are nowadays very much focused on this specific area.
Source: rarediseases.gov; mda.org; Angelini et al., Genetic Neuromuscular Disorders (2017)