SIDS in the The News

A breakthrough discovery for sudden infant death syndrome (SIDS)?

Scientists have just announced the discovery of a gene that might be responsible for a disease involved in sudden death of babies in a small isolated population in Pennsylvania, the Amish. Over a few decades, several infants from a few families died suddenly. Most had had heart and respiratory manifestations which had been investigated by physicians previously, but nothing abnormal was found before they died suddenly. Many of the affected boys had a problem identified at birth because their testes were high up in the abdomen which apparently made it difficult to determine whether they were boys or girl at first glance.

What has just been discovered in four of these babies and their families, is a gene that has a mutation (an abnormality that disrupts the function of a gene) and the affected babies have inherited one faulty gene from each of their parents (i.e., they have two copies of a faulty gene). This gene is involved in some functions related to what is called the autonomic nervous system (the system that controls the automatic function of the heart, respiration, and many other systems).

All parents who have lost a baby to SIDS know, in reading these lines, that the Amish babies did not die of SIDS. These babies were not normal before they died, unlike SIDS babies. And, more than one baby died in the same family over two generations.

Again, researchers and journalists made a large leap with conclusions that might not be appropriate. The discovery of the gene that might be responsible for the death of the Amish babies is a real breakthrough and we are extremely pleased for what it means for the Amish parents of Pennsylvania. Physicians will soon be able to identify the babies that have the mutation (while they are still alive). Scientists will be able to discover more precisely the role of the gene and, perhaps, develop a cure. In 1989, a Canadian team of scientists discovered the gene of another serious disease, cystic fibrosis. That discovery has not brought a cure yet for the disease but has helped the treatment and there is hope that soon a cure might be available.

Will the discovery of the gene involved in the sudden death of infants in the Amish population help determine the cause of SIDS, and more importantly help prevent SIDS? It is too early to answer that question.

For more than a decade now, but especially in the last five years (with the availability of sophisticated genetic techniques), scientists are trying to identify "the SIDS gene". Unlike Cystic Fibrosis, it seems that we are not going to find one single defective gene in SIDS. What has been discovered so far is that some genes seem to interact with certain conditions (infections), with the environment (mother smoking during pregnancy, overheating), or in different populations (African Americans, Indigenous people), to increase the risk of a baby dying of SIDS. Many studies are focusing on the genes involved in the functioning of the autonomic nervous system. It is therefore possible that the discovery of the defective gene in the Amish population of Pennsylvania could help eventually solve the mystery of some SIDS deaths.

At the recent SIDS International Conference in Edmonton, scientists from all over the world talked about their leading research on SIDS. A summary of all the presentations and the latest on genetics will soon be available on the CFSID website, in the newsletter, and in other documents for parents and anyone interested in the topic. We invite you to read the documents and send your comments and questions.

Dr. Aurore C™tŽ
Chair, Research Advisory Committee
Canadian Foundation for the Study of Infant Death