Autosomal dominant centronuclear myopathy

Autosomal dominant centronuclear myopathy (AD-CNM) is a type of centronuclear myopathy, which is a group of rare, inherited conditions that affect the muscles. In AD-CNM, specifically, the severity of the condition and the associated signs and symptoms vary significantly among affected people. In people with a mild form, features of the condition generally don't develop until adolescence or early adulthood and may include slowly progressive muscle weakness, muscle pain with exercise and difficulty walking. Although some affected people will eventually lose the ability to walk, this usually does not occur before the 6th decade of life. In more severe cases, affected people may develop symptoms during infancy or early childhood such as hypotonia and generalized weakness. These children generally have delayed motor milestones and often need wheelchair assistance in childhood or adolescence. Most cases of AD-CNM are caused by changes (mutations) in the DNM2 gene; however, some affected families are reported to have mutations in the MYF6 or CCDC78 genes. The condition is inherited in an autosomal dominant manner. Treatment is based on the signs and symptoms present in each person and may include physical and/or occupational therapy and assistive devices to help with mobility, eating and/or breathing.