Dilated cardiomyopathy – Non-compaction cardiomyopathy [146 genes]

Dilated cardiomyopathy (DCM) is a disease characterized by an increase in ventricular volume (mainly of the left ventricle) associated with wall thinning and deterioration of systolic function. It is one of the main causes of heart failure and heart transplantation, and it presents a high risk of cardiac sudden death. For many years, the cause was thought to be exclusively autoimmune or viral, where endomyocardial biopsy plays an essential role. However, genetic causes are nowadays known to represent 30%-50% of cases.

The prevalence of the disease was estimated to be 1 in 2,500 individuals, although recent studies suggest that it could be much higher.

The genetic test is indicated when there is a suspicion of familial dilated cardiomyopathy:

• It can identify the causal mutation, which confirms the diagnosis of the disease and constitutes an important tool for differential diagnosis since its presentation frequently overlaps with other cardiomyopathies.
• Not all mutations in different genes show a similar behavior-they are usually associated with a specific set of symptoms and with a different prognosis. This helps performing the appropriate risk stratification for the disease and foreseeing possible complications.
• In case a pathogenic mutation is detected, the test can be used with predictive value, constituting the cornerstone of genetic counseling. It is a cost-effective strategy for family monitoring since it allows detecting carriers at risk who must follow appropriate clinical monitoring (given that they are highly likely to develop the disease in the future). Contrarily, non-carriers present the same risk as the general population

The probability of detecting a likely causal mutation of the disease in a patient under suspicion of familial dilated cardiomyopathy is close to 50%. In any case, diagnostic yield depends on multiple variables such as number of relatives affected, clinical suspicion, age, race, origin, etc.