Researchers in Australia have uncovered the first chemical biomarker tied to sudden infant death syndrome, widely known as SIDS, which could help lead to a test that can screen for babies at risk for the tragic condition.
Also known as crib death, SIDS is the sudden, unexplained loss of an otherwise healthy infant during the first year of life, typically while they are sleeping. It is a leading cause of mortality after one month, after birth defects.
“An apparently healthy baby going to sleep and not waking up is every parent’s nightmare, and until now, there was absolutely no way of knowing which infant would succumb. But that’s not the case anymore,” said lead researcher Carmel Harrington, M.D., an honorary fellow at The Children’s Hospital at Westmead in Sydney, who lost her own child to SIDS 29 years ago.
Her team identified the nervous system enzyme butyrylcholinesterase as a strong marker of risk. Dubbed BChE for short, the chemical plays an active role in the brain’s ability to wake up the body from sleep in response to difficulty breathing or another stimulus.
In a study of more than 700 dried blood samples taken from newborns at birth, the researchers found that BChE levels were significantly lower in babies who later died from SIDS. This deficiency could reduce an infant’s ability to wake up and cry out if they are having trouble.
“Babies have a very powerful mechanism to let us know when they are not happy,” Harrington said. “What this research shows is that some babies don’t have this same robust arousal response.”
“This discovery changes the narrative around SIDS and is the start of a very exciting journey ahead,” she said.
According to the Centers for Disease Control and Prevention, there are about 3,400 sudden unexpected infant deaths in the U.S. each year, a category that includes SIDS as well as deaths from unknown causes and accidental suffocation in bed. However, the incidence of SIDS has dropped in recent years due to public health campaigns outlining the risks of overheating and having children sleep on their stomachs.
Next, the researchers plan to develop the BChE biomarker into a newborn screening test and potentially find ways to address the enzyme deficiency. Their work was published in The Lancet journal eBioMedicine.
“This discovery has opened up the possibility for intervention and finally gives answers to parents who have lost their children so tragically. These families can now live with the knowledge that this was not their fault,” said Harrington.