News / Vancouver

Former B.C. coroner finds genetic clue to unexplained death

SFU research points to heart condition possible cause of Sudden Unexplained Death in Childhood.

Megan Carbonetto holds a photograph of her 14-month-old daughter Sarah Rivera who died of unknown causes.

Jennifer Gauthier / For Metro

Megan Carbonetto holds a photograph of her 14-month-old daughter Sarah Rivera who died of unknown causes.

A former B.C. coroner has found a possible genetic clue to sudden unexplained death in children.

“It was based on my past career as a coroner, and periodically having these cases,” said Laura Dewar, who was a coroner for 24 years before returning to Simon Fraser University to complete a PhD in biomedical physiology and kinesiology.

“They’re seemingly healthy people, they die suddenly, and we basically do everything we can in our toolkit to try to find out answers: autopsy, toxicology, family history, and we just can’t come up with answers.”

While Sudden Infant Death Syndrome (SIDS) is more well-known, children over the age of one also sometimes die of unknown causes (Sudden Unexplained Death in Childhood).

It’s frustrating for coroners, while families are left with an agonizing mystery.

“The more that I read about SIDS and SUDC, the more interested I became,” Megan Carbonetto, a Surrey mother whose daughter died at 14 months old in 2016, previously told Metro. “How come nothing has changed in the last 20 years — because really nothing has changed in the last 20 years. There haven’t been very many advancements.”

Dewar contacted coroners and medical examiners across Canada and was able to test a wide range of tissue samples from autopsies of children aged zero to five.

She found a variant in a gene that had not been previously investigated. Some of the genes Dewar looked at “were encoding proteins that really are responsible only when a person is born. They help regulate heart activity in a newborn,” she said.

“In some cases it might be a protein that’s important until the child is two years of age.”

More research is now being done at SFU to investigate whether the mutation is causing an inherited heart rhythm disorder.  

“If a person dies of one of these inherited heart disorders, the heart can look perfectly normal, because it’s an electrical problem,” Dewar said. “It’s not like a person having a heart attack where you’ve got clogged arteries, the blood isn’t pumping properly through the heart.”

In her time as a coroner, Dewar investigated clusters of unexplained deaths in families, in one case as many of five unexplained deaths in one family.

Dewar believes families who have a history of unexplained deaths should ask their family doctors to refer them to one of two clinics in B.C. that specialize in arrhythmic heart conditions. Families and doctors should also be more aware of the subtle signs of these conditions, such as palpitations, chest pain and feeling dizzy or faint when doing physical activity.

She also thinks coroners need to ask for help from geneticists and experts in these types of heart conditions when presented with an unexplained death.

“We could really be missing a number of these cases,” Dewar said. “This is why I really want to see a change in how some deaths are investigated.”

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