Scientists at Boston Children's Hospital and Harvard Medical School have found evidence pointing to a biological cause of sudden infant death syndrome (SIDS). This is reported in an article published in the Journal of Neuropathology & Experimental Neurology.

Although rare, SIDS is by far the leading cause of post-neonatal infant mortality in the United States, with an incidence of 103 in every 100,000 births per year. The criterion for SIDS is the death of an apparently healthy infant before their first birthday, which remains unexplained even after careful investigation. This usually happens during sleep.

The researchers analyzed tissue stored at the San Diego Medical Examiner's Office by examining the brain stems of 70 infants who died between 2004 and 2011. It turned out that the level of activity of the serotonin 2A / C receptor changed compared to control cases, when the cause of death of the infant was determined. The serotonin 2A/C receptor has been shown in rodent experiments to be involved in the wake-up and auto-resuscitation signaling pathway that causes the circulatory system to oxygenate the brain during sleep.

The results of the study show that the identified biological anomaly may explain why some newborns are particularly vulnerable in certain circumstances. According to scientists, SIDS occurs when three factors coincide: the child is in a critical period of cardiorespiratory development in the first year of life, during sleep he encounters an external stressor (facing down) and the presence of a biological anomaly.

However, the relationship between the 2A/C receptor and sudden infant death remains unknown. In addition, currently there are no methods for determining biological abnormalities in the serotonergic system of the brain in infants, so adherence to the rules of safe sleep remains critical.