The term Sudden Arrhythmic Death Syndrome (SADS) is used when healthy people with a structurally normal heart die without warning, without any identifiable natural or toxicological cause. In the United Kingdom alone, SADS causes the death of over 400 young people each year. SADS is thought to result from electrical disturbances in the heart, mediated by mutations in genes that control its rhythm. When people die from SADS, it is important to clinically test their family members for known inherited disorders in heart rhythm, but this can be difficult because some of these disorders cause few clear-cut symptoms.
In a review article, Vishal Vyas and Pier Lambiase discuss two recent, powerful methods that can be used to predict which family members of SADS victims might likewise be at risk. The first is “molecular autopsy”, that is, sequencing the protein-coding part of the deceased person’s DNA, to search for mutations (e.g. in ion channel and heart muscle genes) that could have caused the heart to develop lethal rhythm disturbances. The second is induced pluripotent stem cell technology, that is, culturing heart muscle cells of SADS victims or skin cells from relatives, to investigate how mutations in these cells might cause electrical disturbances. These two methods will also facilitate the development of new drug therapies to stabilize the heart rhythm and prevent cardiac arrests, say the authors.