Cardiomyopathy can have a number of different causes depending on the type of cardiomyopathy. However, in many cases it is a genetic condition that can be passed down through families.
What do we mean by Genetics?
Genetics is the study of genes (part of our DNA), and how we inherit characteristics from our parents. In many cases, cardiomyopathy is a genetic condition. Some cardiomyopathies are not believed to have a genetic origin and others may be a combination of environmental and genetic factors.
Research is still ongoing to understand how certain genes impact the type of cardiomyopathy. There are likely to be a combination of both genetic and environmental factors that impact how a cardiomyopathy effects an individual. Some genes appear to lead to milder forms of cardiomyopathy, others may pose higher risk, for example of arrhythmias.
There are different patterns of inheritance of genes, which effect how DNA is passed between generations. A family pedigree is often the first step to exploring how genetic conditions affect an individual family. A family pedigree usually involves drawing three generations of family members to search for clues about who may have been affected and how those genes have been passed on.
The patterns of who has been affected in a family can provide clues to the specific diagnosis of cardiomyopathy. Identification of a definite genetic cause should lead to genetic counselling and screening of relatives.
- Genetic counselling is part of a DNA testing process for someone that is believed to be affected by a cardiomyopathy.
- Genetic counselling usually involves taking a blood sample to search for genes known to cause cardiomyopathy.
- Results from a DNA test may not always be conclusive, as the search for genes that cause cardiomyopathies is ongoing.
Some genes, described as ‘variants of unknown significance’ (VUS) fall into a grey-zone between definitely being linked to cardiomyopathy and not being associated with cardiomyopathy.
The genetic counsellor will work with you to explore the results of your personal DNA results in order to explore the relevance of VUS.
Genetic tests can help to pinpoint particular genes that may be associated with more severe illness, helping to provide a more personalised treatment plan.
Testing of wider family members, called screening, may help to identify and begin early management of individuals that are positive for genes associated with cardiomyopathy, but are not yet affected by the disease.
Genetic testing is becoming increasingly accurate in locating genes associated with cardiomyopathies, with new genes being ‘updated’ routinely.