SIDS, or Sudden Infant Deat Syndrome, is a sudden and unexplained death of an apparently healthy infant aged one month to one year. It is also known as cot death or crib death, and is said to be the cause of about 2,500 infant deaths each year in the US alone. There has been much speculation, but the definitive cause of SIDS have so far been unidentified.

A recent study of brain samples from infants who dies from SIDS suggest that SIDS may be traced to an abnormality in the brain stem, and supports previous hypotheses that links the vulnerability to SIDS to that same section in the brainstem that regulates serotonin levels. The results of the study have been published in the latest issue of the journal of the American Medical Association. Times Online also ran a report, summarizing the results:

The study suggests that the slight abnormalities in the brainstem may impair a baby's ability to sense high carbon dioxide and low oxygen levels in its body. This would increase the risk that a baby will inhale its own exhaled breath and become deprived of oxygen. Hannah Kinney, the paper's senior author, said: "These findings provide evidence that sudden infant death syndrome is not a mystery but a disorder that we can investigate and some day may be able to identify and treat.

Although some say that a brain abnormality is not unlikely to be the sole cause, understanding the possible risk factors may led to better diagnostics and intervention strategies.

Read the Times Online for the full report.