According to the definition of the , Sudden Infant Death Syndrome “is the sudden and unexplained death of a child under one year of age while sleeping.”
This syndrome affects approximately one in every 1,000 births. And “although it is rare, it is one of the main causes of mortality in children during the first year in Spain and in the developed world”, explains the Dr. Maria Valverde Gomeza cardiologist specializing in hereditary heart diseases at .
Prevention is key to preventing sudden death in babies
It should be noted that the rate of this syndrome decreased significantly in the 1990s, after the measures of pediatric societies on safe sleep in children were implemented.
Among these recommendations are:
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Lay the baby on his back (not on his side or stomach)
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Put the crib in the parents’ room.
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Use firm mattresses.
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Avoid placing loose items in the crib (sheets, blankets, quilts, pillows or toys).
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Do not wrap the baby too much.
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No smoking or
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Breastfeeding and the use of a pacifier have also been shown to reduce this risk.
However, the fact that in recent years the rate has remained stable reflects that there are still unidentified factors.
20% of cases have a genetic origin
Regarding its causes, Dr. Valverde maintains that “the available evidence suggests that sudden infant death syndrome is the result of a combination of biological, genetic, and environmental conditions. Many of these genetic conditions affect the heart and nervous system , being able to be inherited or generated ‘de novo’ in the subject who suffers the event”.
Genetic studies help to identify the genetic causes that make these infants more vulnerable and even, in cases where unfortunately the diagnostic event is the death of a baby, allow the identification of the cause, as well as the risk of it occurring a second event.
“In about 20% of the cases of sudden infant death, a causal mutation is identified. This percentage, similar to that of sudden unexplained death in adults, shows the importance of genetic study in these cases, both in children and adults , as also reflected in the sudden death prevention guidelines”, explains the Dr. Juan Pablo OchoaDirector of Cardiology at Health in Code.
Regarding prevention, there are treatments and recommendations that reduce the risk of fatal events in the main heart diseases that present sudden death. “The identification of a pathogenic variant associated with sudden death allows carrier families to have all the information possible when carrying out family planning”, adds the doctor.
Research, keys to the identification of genetic variants
Health in Code has published several studies focusing on the field of sudden death genetics and channelopathies, diseases that affect the cellular channels of heart cells, leading to ventricular arrhythmias and sudden death.
One of these, focused on research on , arose from the identification in Granada of a series of cases of sudden death or cardiac arrest in young children without detecting an obvious genetic or environmental cause.
Contrary to other hereditary diseases, the parents were healthy, yet several children frequently suffered tragic events at very early ages in the form of severe ventricular arrhythmias.
For this reason, it was decided to genetically sequence DNA samples from 3 affected children to analyze genes encoding proteins involved in signaling and generation of the cardiac impulse, with the finding that all three cases presented a mutation in the gene called calmodulin (CALM). .
He Dr. Juan Jimenez Jaimeza cardiologist at the Virgen de las Nieves University Hospital in Granada, explains that:
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“The protein calmodulin is essential in the regulation of the cardiac action potential. An error caused by a mutation results in the appearance of a prolonged QT interval (measurement of the time between the beginning of the Q wave and the end of the T wave) on the electrocardiogram, which ends up producing a fatal arrhythmia.
In some cases, the inheritance pattern observed in families is that one of the parents is not affected, but carries the mutation and transmits the disease to one or more of the children.
“This explains the dramatic observation of several children affected, in an apparently inexplicable way, by a hereditary disease without any of the parents being sick,” concludes the cardiologist.