The causes of cot death are widely unknown but a new study shows that our genes may be a factor.
A rare genetic mutation associated with breathing muscles in the chest has been linked with the phenomenon, otherwise known as Sudden Infant Death Syndrome (SIDS).
Researchers looked at 278 children who died as a result of SIDS – 84 from the UK and 194 from the US – and the prevalence of the SCN4A gene, which plays a role in muscle control.
Mutations in the gene can cause spasms, making breathing more difficult.
The gene mutation is found in one in every 100,000 people in the general population but was found in four of the 278 babies on the study – a rate of about 1.4 per cent.
While still a fairly small percentage, the researchers say it is significant.
Weakened breathing muscles could be fatal for an infant who suffers a respiratory illness, is exposed to cigarette smoke or becomes tangled or smothered in bedclothes.
The result of this study is a first, according to Professor Michael Hanna of the Medical Research Council Centre for Neuromuscular Diseases at University College London.
However, he said, more research is needed.
“While there are drug treatments for children and adults with genetic neuromuscular disorders caused by SCN4A gene mutations, it is unclear whether these treatments would reduce the risk of sudden infant death syndrome, and further research is essential before these findings can become relevant to treatment.”
Cot death is a relatively rare but still devastating phenomenon.
Fewer than 30 babies die from it in Ireland each year, compared to an average of 134 deaths per year in the 1970s, according to the National Paediatric Mortality Register.
Despite this reduction, SIDS is still one of the leading causes of death among infants, with the majority of cases occurring between the two-month and four-month mark.
Newborns should be left to sleep on their backs in a cot free from pillows, blankets, toys or any other loose items.