New studies highlight potential genetic factors underlying SUDEP

Posted Dec 11 2015 in Brain science; genetics

The genetic causes underlying sudden unexpected death in epilepsy (SUDEP) have been elucidated by a trio of new studies presented at a major medical conference.

In separate presentations at the American Epilepsy Society’s 69th Annual Meeting, the studies cast light on the genetic contributions to the poorly-understood phenomenon, while highlighting possible new strategies for preventing it.

The first of these studies was carried out by the Universities of Melbourne and Sydney, which indicated that genetic variants associated with cardiac sudden death may be to blame for SUDEP.

Examining DNA samples from 62 people who died from SUDEP, it was found that nearly one-quarter of them carried mutations linked to cardiac sudden death, suggesting that irregular heart rhythms may play a role in a significant number of deaths in epilepsy. One-quarter also had genetic mutations associated with epilepsy.

As such, the team theorised that some cases of SUDEP could be prevented by avoiding the use of antiepileptic drugs that affect the heart’s electrical activity, instead recommending beta blockers, pacemakers or implantable defibrillators.

A second study from the University of Michigan identified a specific genetic mutation that may raise the risk of SUDEP in patients with early infantile epileptic encephalopathy, a severe drug-resistant disorder that manifests in the first three months of life.

This occurs due to a specific mutation that created an environment in which the heart has a higher susceptibility to arrhythmias, according to the researchers.

Finally, a New York University Langone Medical Center study revealed that genetic mutations altering the transmission of electrical impulses in the heart and brain could raise the risk of SUDEP, after analysing brain tissue from eight people who had died in this way.

The study found mutations in 607 genes in brain tissue from patients who died from SUDEP that were not seen in the tissue from the living people. Further analysis revealed possible functional effects from 532 of the mutations.

Study author Dr Daniel Friedman, an assistant professor of neurology at New York University, said: “Genetic testing for these mutations could potentially allow for the early identification of people with epilepsy who are at high risk of sudden death.”

Posted by Anne Brown

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