Medical research often takes decades to be translated into practice. But then the new knowledge and techniques can make a big difference in better identifying and curing diseases - such as genetic diagnostics. "Many cardiovascular diseases are caused by defects in one or a few genes. Moreover, such diseases often manifest themselves in adulthood, so it is helpful to detect them early," says Prof. Sabine Klaassen. She is co-author of the consensus paper "Genetic Diagnosis of Cardiovascular Diseases" and head of the Clinical Cardiogenetics research group at the Experimental and Clinical Research Centre (ECRC) as well as a physician at the German Heart Centre of the Charité (DHZC).
The disease-causing genes are present from birth. When a disease develops and how severe it is, varies greatly. It depends on the effect of the disease-causing variant of the sequence. Modulating environmental factors can also play a role. The consensus paper describes the importance, procedure and legal regulations of molecular genetic diagnostics and gives diagnostic recommendations for the most important genetic cardiovascular diseases, of which only a small proportion are currently detected. "With our recommendations, we want to improve patient care: To make an accurate diagnosis, to find the causes of the disease and to decide how the patient can be treated," says Prof. Sabine Klaassen.
Early detection of genetic defects can improve the prognosis and quality of life of patients
Genetic diagnostics is mainly used for differential diagnosis: a diseased heart can have different causes. Genetics can help to identify the disease and its underlying cause - for example, in the case of cardiomyopathies, which are characterised by a thickening of the heart muscle. The most common cause is high blood pressure, but there may also be a genetic defect. Depending on the diagnosis, there are effective therapies.
Another important condition for which genetic testing can help is an inherited heart rhythm disorder. If they are not recognised in time, they can lead to sudden death. Affected patients can be well protected: They receive a defibrillator as a precaution, and beta-blockers also protect them. "It is important to examine relatives and look for this mutation in their genetic material," says Prof. Sabine Klaassen.
The most common cardiovascular disease caused by a single gene defect is familial hypercholesterolaemia (FH). Those affected have an increased risk of suffering a heart attack or stroke at an early age, which is not due to an unhealthy lifestyle or diet. "We need to filter out patients with FH genotype, because their risk of myocardial infarction can be significantly reduced by drugs such as statins or PCSK9 inhibitors," explains Prof. Heribert Schunkert, Principal Investigator at the DZHK site in Munich and final author of the consensus paper. Prof. Ulf Landmesser and Prof. Benjamin Meder are two other DZHK researchers belonging to the group of authors. Prof. Ulf Landmesser from the German Heart Centre at the Charité says: "Genetic diagnostics will play an increasingly important role in the precision management of cardiovascular diseases and at the same time enable the early diagnosis of family members."
More specialist clinics and more public education needed
The paper is a new edition of a position paper from 2015. "Since then, the state of knowledge has improved considerably, and from a technical point of view, wider use of genetic diagnostics would not be a problem," says Prof. Sabine Klaassen. In addition, health insurance companies now often cover the costs of gene sequencing. However, according to the authors, there are still major deficits in the implementation of the recommendations on genetic diagnostics: For example, there are too few specialised outpatient clinics in hospitals and clinics, and more medical staff needs to be trained. "We need more specialised outpatient clinics so that patients can be more accurately diagnosed, centrally cared for and better advised," says Prof. Sabine Klaassen. In addition, the population is still not sufficiently aware of the possibilities of genetic diagnostics.
The DGK is currently working on a pocket guideline with recommendations for general practitioners and hospital staff. Further training courses in cardiogenetics are also in preparation. These will be offered by the medical associations.
Original publication: Consenus paper (in German only)
Scientific contact: Prof. Sabine Klaassen, Charité - University Medicial Clinic Berlin, Clinic for Congenital Heart Disease - Paediatric Cardiology
In the 120/80 DZHK podcast, pediatric cardiologist and basic researcher Sabine Klaassen talks to Christine Vollgraf about her work on hereditary heart muscle diseases in children (available in German only).