Distribution of Cell-cell Junction Proteins in Arrhythmic Disorders

Every week in the UK, 12 apparently healthy and fit individuals under the age of 35 die suddenly, a tragic event known as sudden cardiac death (SCD). The investigators have shown that heritable cardiac disorders affect the distribution of proteins at the cardiac cell-cell junctions, the areas where cardiac cells are mechanically and electrically coupled. This knowledge has helped the investigators diagnose specific heart disorders in individuals thus reducing the risk and incidence of SCD. Yet, the primary material required is a heart sample. A heart biopsy is an invasive process that comes with risks and is not performed unless absolutely necessary. And it is impossible to obtain a heart sample from an individual that may be carrying a disease-causing mutation (and hence be at risk of SCD) but does not yet show evidence of disease manifestation. The investigators recently showed that buccal cells show changes in protein distribution equivalent to those exhibited by the heart,hence providing them with a surrogate tissue for the myocardium. The investigators aim to use buccal smears as a means to identify those at risk of SCD. Patients regularly seen at the cardiology clinics at St. George's Hospital can participate in the study. The investigators shall take a buccal smear simply by rubbing a soft brush at the inside of their cheek and smearing it on a slide. Most individuals willing to participate in the study will only have to provide the investigators with a sample once. However, in selected cases (for instance, if the patients show disease progression or have a change in medication) they may be asked to provide the investigators with a subsequent sample during one of their scheduled follow-up visits. The process takes only a few seconds, is totally risk- and pain-free and it is anticipated to have great implications in diagnosis and patient management.