Pediatric Cardiomyopathy
Genetic Testing

Genetic Testing for Cardiomyopathy

Genes are packages of genetic information that tell our bodies how to develop and function. Cardiomyopathy can be caused by a change or mutation in a gene that encodes proteins important for the contraction or squeeze of the heart muscle. There are four types of cardiomyopathy. Genetic causes for each type are different as well as the likelihood of whether or not that gene will be passed on.

Dilated cardiomyopathy
Mutations in these genes result in familial DCM, which is inherited in an autosomal dominant manner. A parent that carries a gene mutation will have a 50 percent chance of passing it on to each child.

Hypertrophic cardiomyopathy
Gene mutations in more than 20 genes have been identified that cause HCM. HCM is most often inherited in an autosomal dominant manner. A parent that carries a gene mutation will have a 50 percent chance of passing it on to each child.

Left ventricular non-compaction cardiomyopathy
A parent that carries a gene mutation will have a 50 percent chance of passing it on to each child.

Restrictive cardiomyopathy
Most often, RCM is inherited. A parent that carries a gene mutation will have a 50 percent chance of passing it on to each child.

 

Genetic testing is available to look for mutations in the genes known to cause cardiomyopathy. This type of testing is done by a blood sample. It is best to begin genetic testing in a family with an individual who is known to have the type of cardiomyopathy. If a gene mutation is found in someone with that type of cardiomyopathy, genetic testing for the same mutation can be offered to close family members. Finding a gene mutation in other family members will help identify family members who may be at risk to develop heart muscle disease and who should have cardiac screening.

A genetic counselor and/or geneticist can assess the family history and provide information about the chance that there is a genetic predisposition to cardiomyopathy. A genetics professional can also explain and facilitate genetic testing and interpret results for patients and families.

Screening for Family Members 

All first degree relatives of an individual who has cardiomyopathy should undergo routine cardiac evaluation. This includes parents, brothers, sisters, and children. If a genetic mutation causing cardiomyopathy in an individual is known, screening is recommended for those family members proven to also carry the gene mutation. Routine cardiac screening would not be recommended for family members who did not inherit the gene mutation.

The timing of routine cardiac screening for family members should be discussed with a cardiologist and genetics professional who have experience in caring for individuals with cardiomyopathy. How frequently an individual should be evaluated is based on published guidelines and the individual’s age, personal medical and family history.

The best screening tools include echocardiography and magnetic resonance imaging (MRI).