Australian researchers, led by Dr Carmel Harrington, have identified a biomarker that can detect babies more at risk of Sudden Infant Death Syndrome (SIDS) while they are alive. After losing her son, Damien, to SIDS 29 years ago, Dr Harrington, a research student at Children's Hospital at Westmead (CHW) has dedicated her career to finding answers for the condition.
SIDS is the unexplained death of a healthy infant less than one year of age, during a period of sleep. In India, as per a 2019 data, 32 infant deaths occur per 1000 live births. In 2019, the sudden unexpected infant deaths rate in the US was 90.1 deaths per 100,000 live births. SIDS is one of the leading causes of sudden unexpected infant deaths in the US though its rates have declined from 130.3 deaths per 100,000 live births in 1990 to 33.3 deaths per 100,000 live births in 2019 as per a report by the US CDC.
Butyrylcholinesterase (BChE) has been identified by the researchers as the biochemical marker that can help prevent death in infants.
What is SIDS?
SIDS is sudden infant death syndrome. It is one of the leading causes of death in new born babies. It is also known as 'cot death'. Babies who die of SIDS seem to be healthy before being put to sleep. These babies do not show any signs of struggle.
Who are at higher risk of SIDS?
Babies between 1 and 4 months of age are at higher risk of dying due to SIDS. As per reports, over 80% SIDS related deaths occur before the babies reach six months of age.
SIDS: What does the study say?
In the study, published in The Lancets eBioMedicine, the team analysed BChE activity in 722 Dried Blood Spots (DBS) taken at birth as part of the Newborn Screening Programme. BChE was measured in both SIDS and infants dying from other causes and each compared to 10 surviving infants with the same date of birth and gender.
What is the role of BChE?
BChE plays a major role in the brain's arousal pathway and researchers believe its deficiency likely indicates an arousal deficit, which reduces an infant's ability to wake or respond to the external environment, causing vulnerability to SIDS. The findings showed BChE levels were significantly lower in babies who subsequently died of SIDS compared to living controls and other infant deaths, said lead author Dr Harrington.
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Dr Harrington explains BChE role in SIDS
"Babies have a very powerful mechanism to let us know when they are not happy. Usually, if a baby is confronted with a life-threatening situation, such as difficulty breathing during sleep because they are on their tummies, they will arouse and cry out. What this research shows is that some babies don't have this same robust arousal response," Dr Harrington said.
"This has long been thought to be the case, but up to now we didn't know what was causing the lack of arousal. Now that we know that BChE is involved we can begin to change the outcome for these babies and make SIDS a thing of the past."
Can SIDS be avoided?
The US CDC suggests parents and caregivers to keep the sleeping cot of the baby in the same room where they sleep. It suggests the parents to sleep in the same room as the baby until the baby is 6 months old.
With this research study, the next steps for researchers is to begin looking at introducing the BChE biomarker into newborn screening and develop specific interventions to address the enzyme deficiency.