Further cot death susceptibility genes identified

New research by scientists at Manchester University, UK, has shed further light on Sudden Infant Death Syndrome (SIDS). The research has found that babies with particular variants of three genes are up to 14 times more likely to succumb to the condition.

The researchers, led by Dr David Drucker, compared DNA taken from 25 babies who had died from SIDS with DNA from unaffected infants. Significant differences were found in VEGF, a growth factor important in lung development and also associated with the immune system, and in two genes involved in immune responses (IL-6 and IL-10, both cytokines). Previous research by Dr Drucker's team, in collaboration with a group from Lancaster University, had found that SIDS is associated with common bacteria that can be found in the upper airways that infants less than a year old may lack immunity to. The new research proposes that babies with the particular gene variants may have a combination of under-developed lungs, compared with normal babies, and an excessive immune response to the common bacteria. Babies are most vulnerable between the ages of two and four months. Other risk factors, such as smoking and placing the baby in the wrong position while sleeping, add further danger to susceptible infants.

Dr Drucker, speaking about the research, noted that as well as possible therapeutic application this new knowledge could also help to avoid miscarriages of justice. 'This research greatly advances our understanding of the basic causes of SIDS, which is not a single disease but a collection of different causes of death', he said, adding that 'being able to detect high-risk babies means that health care and social provision can be aimed at the most vulnerable infants. In theory, commercially available and licensed human immune serum could be given to those children most at risk'. He continued: 'Forensic scientists would be able to assess the likelihood of a baby dying from SIDS through genetic measurements and so help prevent the sort of tragic miscarriages of justice that have happened in the past'. The research is published in the journal Human Immunology.