Simple cheek swab could predict sudden cardiac death risk

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria:• Participants will include patients diagnosed with a heritable arrhythmic disorder (including arrhythmogenic, hypertrophic and dilated cardiomyopathy, cardiac sarcoidosis as well as cardiac channelopathies; Long QT syndrome, Brugada syndrome and catecholaminergic polymorphic ventricular tachycardia) followed at the Inherited Cardiac Conditions (ICC) service of St. George's University Hospitals NHS Foundation Trust. * Family members of victims of SCD evaluated at the same clinic for risk assessment and diagnosis. These groups include both individuals with clear disease manifestation (termed "affected") as shown by conventional diagnostic approaches (electrocardiography, echocardiography, cardiac MRI, Holter monitoring) as well as potential carriers of disease-causing mutations who, however, may not/not yet manifest any overt sign of cardiovascular abnormalities (termed "carriers"). These are typically family members of probands diagnosed with a heritable arrhythmic disorder or family members of a sudden cardiac death victim. * All individuals that fall in the above categories will be included regardless of their management (medication, devices, and surgical procedures). * Individuals with co-existing conditions will also be included and their medical history will be taken into account when interpreting the results of the immunohistochemical analysis. * Adult individuals (\>18 years of age). * Pregnant women will be included as the approach used is not in any way harmful or uncomfortable. * All individuals must have provided the study team with a signed informed consent in order to participate in the study. Exclusion Criteria:• Children under 18 years of age * Individuals lacking decisional capacity. * Individuals with non-heritable, non-arrhythmic cardiac disorders (such as ischemic heart disease or inflammatory disorders) followed at St. George's University Hospitals NHS Foundation Trust. * Non-English speakers will be excluded from the study unless a translator is present who can thoroughly explain to them the research question/plan in order for them to provide an informed consent.