Some cardiomyopathies are caused by specific genetic mutations that exist in a family and can be passed down. There are different ways that a child may inherit cardiomyopathy from their parent(s).
Autosomal Dominant Transmission
A parent carrying a genetic mutation has a 50 percent chance of passing the mutation on to a child of either gender. The parent may either be diagnosed with cardiomyopathy or may carry the mutation without any symptoms of the disease.
Autosomal Recessive Transmission
Both parents carry a mutation that when combined can cause a cardiomyopathy-related disease in their child, but the parents do not have the disease themselves. The chance their child of either gender will have both mutations is 25 percent.
A parent has a genetic mutation on their X chromosome, and may or may not have symptoms of the disease. More commonly, mothers can pass the gene to either their son or daughter with a 50 percent chance, but sons are more likely to have the cardiomyopathy-related disease.
Nearly all cases of mitochondrial transmission happen through the mother, who may or may not shows signs of the disease. Potentially all of the children can be affected, but the symptoms and severity can vary from child to child.
In some cases, a child may be the first person in the family to develop cardiomyopathy because of a new or de novo gene mutation. While it is unlikely that the parents will have another child with the same condition, the affected child can transmit the genetic mutation to his or her children in the future.
An Overview of Inheritance for Cardiomyopathies is a resource that was jointly developed by the Children’s Cardiomyopathy Foundation and the American Heart Association, and it provides additional information on inheritance patterns.