Several studies have linked sudden infant death syndrome (SIDS) to mutations in a gene, called IL-10, that helps control the body's immune function.
The same UK team who established this relationship have subsequently found that that is also the case for IL-6, a protein involved in inflammation, and vascular endothelial growth factor, or VEGF, a protein that stimulates blood vessel growth.
Therefore, "Some SIDS cases must have a biological basis," lead investigator Dr. David B. Drucker told Reuters Health.
In the journal Human Immunology, Drucker and colleagues at the University of Manchester describe their post-mortem study of tissue specimens from 25 babies whose deaths were attributed to SIDS.
They found that a specific variant in VEGF and one in IL-6 were significantly over-represented in the SIDS group compared with a control group.
The researchers note that the study group was not the same as the one in which the IL-10 findings had been made. However, they point out that if a given infant had all three mutations, the odds of being a SIDS victim would be greater.
Exposure to cigarette smoke and other hazards such as being put to sleep in the "wrong" position would increase the SIDS risk even more.
"Being able to identify high risk babies could help target preventive measures," noted Drucker, "and laboratory tests some time ago found that a commercially available immunoglobulin should help protect babies."
"It will now be possible," he concluded, "to define a suitable cohort of at-risk babies for a clinical trial."
