September 2025—When someone dies suddenly and unexpectedly, a forensic autopsy is often performed to identify the manner and cause of death. However, up to 30 percent of autopsies fail to identify any underlying anatomic or toxicologic etiologies, and the autopsy classification may be sudden unexplained death. This is particularly concerning in young people, in whom the cause could be an inherited genetic condition that could also affect family members. Therefore, postmortem genetic testing, also known as a molecular autopsy, may have utility in identifying underlying inherited diseases that could contribute to death. In many cases, sudden death is due to cardiac factors, but the type of cardiac dysfunction may depend on age.