Genetic Findings About Sudden Infant Death Could Unlock the Case of Kathleen Folbigg
Thu, April 22, 2021

Genetic Findings About Sudden Infant Death Could Unlock the Case of Kathleen Folbigg


A team of researchers from the Australian National University (ANU) have recently found a new gene mutation that is likely to cause sudden unexpected death in infancy and childhood. This finding could not only help mothers across the globe but may also unlock the case of Kathleen Folbigg, an Australian convicted of murdering her three infant children and manslaughter of her fourth child.

The case of Kathleen Folbigg

In 2003, Folbigg was convicted by a jury and labeled by media as the “child killer.” However, she has always maintained her innocence. All of her children were between 19 days and 18 months old when they died between February 1989 to March 1999. In a 2007 study that appeared in the Australian Journal of Forensic Sciences, Sharmila Betts and Jane Goodman-Delahunty from the University of South Wales’ School of Psychology wrote about the case of Folbigg and reviewed the challenges that medical experts face when examining the unexplained multiple infant deaths.

Betts and Goodman-Delahunty said that the case against Folbigg relied on the fact that she found her kids after death while their bodies were still warm. The public found it incomprehensible that a mother could fatally harm her children and continued to have more kids. The defense argued, “there was a lack of consensus among medical experts as to the cause of each child’s death.” At sentencing, Folbigg’s own tragic childhood history was revealed.

New ANU research, which appeared in Medical Xpress, now highlights that two of Folbigg’s daughters – Sarah and Laura- both carried a novel variant “G114R” in the gene called CALM2. The researchers said that such a variant in a maternally-inherited gene is likely to cause sudden unexpected death in infancy and childhood.



The G114R variant

Dr. Todor Arsov and Professor Caroal Vinuesa first discovered the novel variant G114R in the CALM2, which is believed to cause lethal cardiac arrhythmias. The G114R variant in such a gene was found in Folbigg and her two daughters. The researchers believe that such a variant could raise serious doubts about the woman’s conviction.

CALM2 genes are also linked with various life-threatening arrhythmias as well as complications with the heartbeat. Folbigg herself was a mildly symptomatic carrier of CALM2 genes. More than 13% of people with pathogenic CALM gene mutations remain healthy, the authors added.

The researchers are comprised of world-class experts, including experts in inherited cardiac arrhythmias and leading cardiologist Professor Peter Schwartz. He said that a fatal arrhythmic even in both of Folbigg’s daughters could have been caused by their intercurrent infections. On autopsy, Laura was found to have florid myocarditis and had a respiratory infection. On the other hand, Sarah had been started on antibiotics and had a croupy cough.




The ANU team’s finding of a previously undiscovered gene variant is a “reasonable explanation” for the “natural cause of their deaths,” referring to Folbigg’s children. Aside from this, their genetic findings could also help mothers across the world. Genome sequencing can potentially explain sudden infant death syndrome (SIDS) and sudden unexpected infant deaths (SUID).

In the US alone, there were about 1,400 deaths due to SIDS, according to the CDC. About 1,300 deaths were due to unknown causes and 99 deaths due to accidental suffocation and strangulation in bed. Louisiana, West Virginia, Alaska, Mississippi, Arkansas, and Alabama had the highest SUID rates while Vermont and the District of Colombia had the lowest SUID rate, which was 37.4 per 100,000 live births.

Meanwhile, the Australian Institute of Health and Welfare shares that most Australian children are healthy, safe, and doing well. However, infant deaths still occur at a rate of 3.3 per 1,000 live births in Australia. The leading causes of infant death in 2017 are other perinatal conditions (29%), congenital malformations in the circulatory system (7%), other congenital anomalies (16%), SIDS (3%), signs, symptoms, and abnormal findings except for SIDS (7%), all other causes (14%), fetus and newborn affected by maternal complications of pregnancy (8%), fetus and newborn affected by complications of placenta, cord, and membranes (9%), and disorders of short gestation and low birth weight (8%).



Infant mortality

The Organisation for Economic Co-operation and Development, an intergovernmental economic organization founded to stimulate economic progress and world trade, shares Australia’s infant mortality in the following years: 2005 (4.9 deaths per 1,000 live births), 2006 (4.7), 2007 (4.1), 2008 (4.1), 2009 (4.2), 2010 (4.1), 2011 (3.8), 2012 (3.3), 2014 (3.4), 2016 (3.1), and 2018 (3.1).

Although not the focus of the experiments conducted by ANU researchers, the team also shared they found a different genetic mutation in Folbigg's two boys Caleb and Patrick. Such a mutation may also explain their deaths too. The two mutated copies of a gene, which when defective, can cause early-onset lethal epilepsy in mice. Evidence shows that Patrick had epilepsy for four months before he died.

Professor Vinuesa said that the process of sequencing the whole genomes from the kids’ neonatal heel-prick blood cards that were already more than 20 years old is an “incredible” achievement.

However, their investigations into the two boy’s gene variants are still in the preliminary stages so they focused on explaining more on the two girls’ variant since it had been studied in detail, they added.

Medical experts have suggested that to reduce the risk of SIDS, parents can put their baby to sleep on his back, use a firm sleep surface, and put away stuffed animals and fluffy blankets out of his crib. It is also advised not to overheat the room where the baby sleeps and mothers should not smoke when they are pregnant or not allowing someone to smoke around the baby. Breastfeeding is also advised to reduce the baby’s risk of SIDS.

SIDS is still considered a mysterious syndrome. Even its definition itself says that its cause cannot be determined. So far, researchers said that SIDS has a biological basis and they are continuing to study to determine to identify the at-risk babies and determine the underlying causes of SIDS.

The fresh genetic evidence unveiled by ANU researchers does not just raise new questions about the conviction of Folbigg but a possibility of reducing babies’ risk of SIDS.