Inheritance of Cardiomyopathy

Inheritance is a term used to explain how genetic information is passed from a parent to their child.

We share common genetic information with our family members, as we receive half our genetic information from each of our parents. Since we have two copies of every gene, we receive one copy from each parent. 

Cardiomyopathy is most commonly inherited as an autosomal dominant condition, meaning you only need one copy of the gene to have a genetic change (variant) for the cardiomyopathy to develop.

there are the genes of two parents and their child. Parent 1 has two blue genes, Parent 2 has two purple genes. Their child has one blue gene and one purple gene.

In inherited cardiomyopathies, one copy of a gene involved in your heart function may contain a genetic change (variant) that stops the heart from working as it should. A variant is a genetic change in the body’s instructions which alters instructions of the gene. A disease-causing genetic variant in an instruction for the heart that can cause cardiomyopathy.

This type of inheritance is known as autosomal dominant inheritance, as having only one copy of genetic change can result in cardiomyopathy. A person with an inherited cardiomyopathy, will have one copy of the gene with the genetic change (variant) and one unaffected copy.

Autosomal dominant inheritance affects all genders equally and cannot “skip” a generation.

Example of gene changes leading to cardiomyopathy. Left example shows two copies of the same gene one has a change which leads to cardiomyopathy. This is what the genetics of someone with cardiomyopathy would look like. Right hand side shows two genes without a cardiomyopathy gene change. Showing what the genetics of someone unaffected by cardiomyopathy would look like.

If this person has children, each child will have a 1 in 2 (50%) chance of inheriting the genetic change (variant) that causes cardiomyopathy. This is because a parent can only pass down one copy of their genes to their children. The other parent will pass down the other copy of the gene to the child.

Parent one has cardiomyopathy and parent two does not have cardiomyopathy. There is a 50% chance that their child had cardiomyopathy and a 50% chance their child will not have cardiomyopathy.

In some rare cases, a person may have a genetic change (variant) that has not been inherited from their parents. Instead the genetic change (variant) is seen for the first time in that person. This means siblings and parents are not likely to develop a cardiomyopathy. However, the genetic change (variant) can still be passed down to any children of the affected person.

It is important to remember we have no control of what genes we pass on.

Looking for more information:

Information for Family Members
Genetics and Cardiomyopathy
Genetic Testing for cardiomyopathy