No one could explain to Carmela Teresa Harrington why her son Damien suddenly died in his sleep. It was 29 years ago. Biochemist Harrington worked as a lawyer at the time and was the mother of three children. “They just told me it was a tragedy. But it just didn’t fit in my head,” Harrington recalls.
Three years later, her close friend’s baby also died of sudden infant death syndrome (SIDS), also known as “crib death.” Biochemist Harrington has decided to embark on intensive research, which she is funding throughcrowdfunding .
In the end, her perseverance and dedication paid off. Harrington believes her research team at Westmead Children’s Hospital, in collaboration with the University of Sydney, has indeed found the cause of SIDS. According to results of this studypublished in the specialized journal The Lancet eBioMedicine, the cause of sudden death may be an enzyme that blocks the infant’s brain and thus prevents the child from life-saving awakening during breathing problems.
Sudden “death in the cradle” in a dream
Sudden Infant Death Syndrome (SIDS) occurs without warning. Mostly when the baby is sleeping. Thus, research has shown that children have a defect in the wake-up mechanism that normally causes a child to wake up when they have difficulty breathing.
Each person has natural command and control systems that provide support for breathing, for example, by measuring the carbon dioxide content in the blood and reacting accordingly in case of lack of oxygen. If an increased amount of CO2 in the blood is registered in the corresponding area of the brainstem, for example, due to the fact that you, say, are covered with a blanket so that you do not have enough oxygen, then breathing is automatically stimulated and the person wakes up.
However, in the case of sudden infant death, according to the Harrington research team, this awakening mechanism is prevented, as was previously believed, not by a genetic defect, but by an enzyme that blocks the mechanism of awakening a person from sleep in the brain.
For their study, the team analyzed dried blood samples from more than 60 deceased infants, who were between one week and two years old at the time of sudden death.
Enzyme deficiency blocks the brain
Comparison of blood samples with samples of healthy children showed that in those who died from sudden infant death syndrome, the activity of an enzyme from the group of esterases – butyrylcholinesterase (BChE) – was significantly lower.
Because the BChE enzyme plays an important role in communicating information to the body through the brain, Harrington’s team concluded that there must be a link between enzyme deficiency and sudden infant death syndrome, especially during sleep. Because a deficiency of butyrylcholinesterase can lead to prolonged cessation of respiratory movements, that is, to cessation of breathing during sleep. Moreover, the duration of apnea varies depending on the degree of enzyme defect.
Early screening test and drugs could save children
If further research confirms butyrylcholinesterase deficiency as a cause of sudden infant death, it could save many children’s lives in the future. The BChE enzyme can be used as a biomarker to identify risk.
Harrington’s team intends to develop an appropriate screening test that will identify high-risk children early and protect them from sudden infant death syndrome. However, for this it is necessary to develop drugs that can return an important enzyme, that is, protein, to normal, as it happens in the vast majority of children.