DNA, or deoxyribonucleic acid, is the hereditary material that carries a person’s genetic information and is located in each body cell. A gene is a specific part of DNA that gives the body instructions on how to grow and develop properly. When there are genetic mutations, alterations in the DNA change the instructions that regulate certain body functions like how the heart pumps. A mutation in one or more genes can cause cardiomyopathy in children.
There are several genetic mutations known to cause cardiomyopathy, and genetic tests are available to screen for certain common mutations. The Genetic Mutations page lists common genetic mutations associated with pediatric cardiomyopathy.
Genetic mutations may result in isolated or primary cardiomyopathy affecting only the heart, or they may lead to secondary cardiomyopathy associated with other problems such as muscle weakness, poor growth and learning disabilities.
Patterns of Inheritance
Cardiomyopathy can be inherited a number of ways. An overview on how cardiomyopathy can be transmitted is available on our Genetic Inheritance page. Children with primary cardiomyopathy – when the disease affects only the heart – can inherit the disease through autosomal dominant inheritance. Approximately 50 to 60 percent of children with hypertrophic cardiomyopathy and 20 to 30 percent of children with dilated cardiomyopathy and restrictive cardiomyopathy have a family history of the disease.
Secondary cardiomyopathy is a result of a different, underlying disease that affects many areas of the body, including the heart and other organs. Associated Genetic Disorders lists several forms of secondary cardiomyopathy found in children. The disease may be inherited through autosomal dominant, autosomal recessive, X-linked or mitochondrial transmission, or as a sporadic occurrence. Examples of such secondary cardiomyopathies include Noonans syndrome, Pompe, Barth syndrome, Duchenne or Becker muscular dystrophy, and fatty acid oxidation disorders. These diseases are usually not immediately or easily diagnosed, and they often require genetic testing and evaluation by other specialists.