Sudden cardiac death (SCD) of a young person is a devastating and tragic ultimate outcome of a collection of cardiac disorders. The death often occurs in people who were thought to be well, by definition is sudden, can occur without prior warning symptoms, and is often the first presentation of an underlying genetic heart disease. Many of the genetic heart diseases are caused by single genetic variants that have a one-in-two chance of being inherited by each first-degree relative. Therefore, the surviving family not only have to deal with the sudden loss of a young family member but are also left with the compounding uncertainty as to whether SCD could strike again in another family member. In recent years, our ability to identify the causes of SCD in the young has improved. Finding a precise genetic cause of death allows cascade genetic testing of family members to identify those who are at risk and facilitate early intervention to prevent another sudden death. Thus, investigations to define the precise cause of SCD of a young person not only bring a level of closure for the family but are also of vital clinical relevance.