Arrhythmogenic cardiomyopathy [30 genes]

Arrhythmogenic cardiomyopathy is characterized by the replacement of healthy myocardium by fibroadipose tissue, together with the presence of ventricular dysfunction and malignant cardiac arrhythmias. Classically, the description referred to forms of the disease with exclusive involvement of the right ventricle, but currently, biventricular forms or forms with left ventricle involvement are recognized. Among the diagnostic criteria is the presence of a pathogenic genetic variant, so in this entity, the genetic study of the patient and his family is especially important.

The identification of carriers allows us to make lifestyle recommendations that prevent or delay the development of the disease.

The prevalence of the exclusive right-sided form of involvement has been classically estimated at around 1/5,000 individuals, although if left-sided forms of involvement are considered it is much higher, considering that up to a third of patients diagnosed with dilated cardiomyopathy (sometimes the diagnoses overlap) may present an arrhythmic form of the disease.

Genetic study in arrhythmogenic cardiomyopathy allows:

• A diagnostic confirmation, which is often an important support in the differential diagnosis. In this disease, the identification of a pathogenic variant in related genes is part of the diagnostic criteria.
• The most precise study of a patient’s relatives, so that carriers have access to an early/preclinical diagnosis and non-carriers can be safely discharged from consultations of cardiology.
• An approach to the prognosis of each patient, depending on the type of genetic variant identified. Our scientific group has been a pioneer in this type of genotype-phenotype correlation analysis.

Once the diagnosis of arrhythmogenic cardiomyopathy is established in a patient, a genetic testing is indicated, as recommended by clinical guidelines and current consensus documents that address different aspects of the disease. On the other hand, the identification of a pathogenic variant constitutes a diagnostic criterion for the disease.

The probability of identifying a genetic variant that explains arrhythmogenic right cardiomyopathy is around 50-60%. It is not uncommon to find more than one pathogenic variant.