Emery-Dreifuss muscular dystrophy is a rare form of MD that affects only males. Symptoms may begin in childhood or adolescence. The condition causes slowly progressive (worsening) weakness in the muscles of the shoulders, upper arms, and lower legs and joint stiffness (contractures). Life threatening heart problems commonly occur in those with this form of MD. These heart problems may also occur in carriers of the gene that causes Emery-Dreifuss MD (people who have the gene for the disease, but do not have other symptoms).