Genetic testing may reveal the cause of sudden death in a young person
Keywords:The reason for an unexplained sudden death of a young person may be a rare hereditary disease that can remain undetected in standard examinations. Genetic testing is an important part of investigating the cause of an unexpected sudden death, especially in adolescents. Genetic testing may also help to identify relatives who are at risk of sudden death, and to prevent possible severe cardiac events.
One such rare hereditary disease is associated with a defect in the gene PPA2. It may cause extreme sensitivity to alcohol and increase the risk of severe, or even fatal cardiac events.
A recent Finnish study provides new information on this disease. The study found that a person with the PPA2 gene defect may be completely asymptomatic well into adulthood. However, the first sign of the disease may be a severe cardiac event. The cardiac event may be triggered by a very small amount of alcohol.
“The PPA2 disease may cause no symptoms for a very long time, and a severe cardiac event may be the first symptom. If the gene defect is identified before this, the risk can be reduced in a simple but very important way, which is abstinence from alcohol”, explains Postdoctoral Researcher Krista Heliö.
A recommendation in the journal Circulation, published by the American Heart Association, states that carriers of the PPA2 gene defect should abstain from alcohol completely. The extreme sensitivity to alcohol associated with the PPA2 disease means that even minor amounts of alcohol can trigger a severe cardiac event.
Genetic diagnosis provides important information for the entire family
The study emphasizes the importance of postmortem genetic testing when the sudden death of a young individual is otherwise unclear. A rare hereditary disease is not always detected in a regular autopsy.
Identifying a gene defect may help find out the cause of the death and also lead to genetic testing of the living relatives. This can help identify individuals who share the same hereditary risk of a severe cardiac event.
“An unexplained sudden death of an adolescent is always a terrible tragedy for the family. Uncertainty over the cause of death may become a long-term burden. If a hereditary condition can be identified as the cause, the information can be used to protect other family members. The PPA2 disease is a mitochondrial disorder, which can sometimes manifest exclusively as a cardiac condition. This is one example that shows why genetic testing in these situations is important”, says Tiina Ojala, professor of pediatric cardiology.
“The extreme sensitivity to alcohol associated with the PPA2 disease is an example of a very rare hereditary condition that is associated with a risk of a fatal cardiac event. There are other, far more common, hereditary cardiac arrhythmias and myocardial diseases, which may cause a sudden cardiac death, and they can be detected with genetic testing,” explains Associate Professor Tiina Heliö.
This study was conducted by a multidisciplinary research group from HUS, University of Helsinki, and Tampere University. Postdoctoral Researcher Krista Heliö was responsible for the implementation of the study, and Associate Professor Tiina Heliö and Professor of Pediatric Cardiology Tiina Ojala were responsible for supervision.
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