Cot death or Sudden Infant Death Syndrome (SIDS) is a rare but unexplained and tragic occurrence where babies between ages two and four months who are apparently healthy die unexpectedly during sleep. SIDS is responsible for around 300 and 2400 deaths in the United Kingdom and United States of America yearly. Researchers have now found a genetic link that could explain the occurrence and risk of such incidents. The study appeared in the latest issues of the journal Lancet.
Professor Michael Hanna of the MRC Centre for Neuromuscular Diseases at University College London, one of the lead authors of the study explained that there is a rare genetic mutation that can affect the muscles that assist in breathing. If these babies who have the mutation slept the wrong way – on their chest instead of on their back – they may be at a greater risk of SIDS, he said. He explained that earlier the research focused entirely on the heart and the brain of the babies and their anomalies when these deaths occurred. He added that there are several more genes that could influence breathing muscles. These need to be studied in detail and examined to understand the roles they could be playing in breathing in the babies.
For this study the team of doctors found that there are mutations in the SCN4A gene that can code for an important cell surface receptor. This gene is expressed in low amounts in the breathing muscles after birth but over the first couple of years of life, it increases. The team looked at 278 babies who had died of SIDS. Of these 84 were from UK and 194 from the US. The genetic make-up of these babies was compared to 729 matched adults who had never had any heart disease, lung disease or disease of the nerves and brain. They noted that four of the babies had a rare mutation but none of the adults carried that mutation. This mutation is rare in general population – less than five people in every 100,000. Obtaining four among 278 babies meant that the risk of this mutation was high among babies who died of SIDS. The authors explained that these babies who carried the gene mutation were more at risk of death if they got tangled in bed clothes or slept in wrong positions.
According to Hanna this is a start and more research is needed. As of now the evidence is relatively strong. He said it gives parents who wish to go for IVF to get another baby a chance to rule out this genetic mutation in the embryos they select. He said that there are drugs that could be given to babies who have this mutation to protect them for the initial months of their lives from SIDS.
To prevent cot deaths, all parents should follow certain “safe to sleep” guidelines for their babies. These include laying their babies on their back and not allowing sleeping on their chests and tummies. The surface of the cot should be firm with a tight-fitting sheet. Bed clothes may strangle or suffocate the babies so the cots should be free of loose bed clothing. Parents should not smoke near their babies and not share beds with the babies. Babies should not be placed in parent’s bed for at least first six months but may share the bedroom. Sharing the bed room can reduce the risk of SIDS by half the recommendations say.
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