Researchers at Simon Fraser University have received nearly $100,000 from the Stem Cell Network to better determine the cause of death in cases of Sudden Infant Death Syndrome (SIDS). The funding is in addition to a $160,000 grant from the Canadian Institutes of Health Research.
SFU biomedical physiology and kinesiology professor Glen Tibbits, says one of his PhD students, Laura Dewar, worked as a coroner for over 20 years investigating SIDS cases. “Laura was extremely frustrated as she would have to go back to the parents and was not able to say why their child had died. Not only are parents feeling incredibly guilty and grieving because of the loss of their child but they have no idea about other children they have and whether they might be at risk.”
SIDS is one of the most common causes of death for babies between one month and a year old, according to HealthLink BC. There are no symptoms or warning signs.
The research team received 200 infant tissue samples from the medical examiner in Manitoba where the cause of death was not identified despite thorough autopsies, toxicology, microbiology, X-ray and other analyses.
Tibbits, Dewar, Sanam Shafaat Talab and Eric Lin studied the samples to see whether some of the babies had died from sudden cardiac arrest (SCA). He says SCA is not like a heart attack “because it doesn’t leave any imprint on the heart itself after death. With SCA “the heart becomes electrically unstable and stops beating. In an autopsy, when they look at the child, they can’t see that this happened and so they don’t know how the child died.”
Through genetic sequencing the team found 10 identical mutations and Tibbits says they are developing a tool to see if this mutation was a likely cause of death in these infants. Researchers use CRISPR gene-editing technology to insert the mutation these kids had into normal stem cells, which were turned into beating heart cells.
Researchers stimulated the heart cells to simulate exercise and introduced hormones to simulate stress. Tibbits says only the heart cells with the mutation began “beating chaotically.”
“We have pretty good evidence that mutation was the reason they died,” he says, which is important because it helps parents realize that it wasn’t their fault. “It also allows us to say that any future kids carrying this mutation are at risk.”
Researchers will be developing the screening process and studying if drugs or blockers can prevent SIDS in children that have this heart mutation. “It turns out this particular mutation is only something that is expressed in the heart for the first two years of life,” says Tibbits. “If they can survive that period they’re fine because that gene isn’t being expressed but in the first two years if a series of events happen simultaneously, perhaps exercise and stress, and they have the mutation, they could die instantly. We want to find out who’s at risk and how to prevent them from succumbing to that risk factor.”
