A crib-death gene?
Their parents knew something was wrong. The babies cried with the sharp, staccato pitch of a goat's bleating. They had trouble breathing and were easily startled.
There were other, stranger symptoms. The boys had underdeveloped genitals, and some were thought to be girls, even given girls' names when they were born. And then, before their first birthdays, without warning, they died.
This pattern was familiar to Erik Puffenberger. A geneticist at the Clinic for Special Children in Strasburg, Pa., Puffenberger treats obscure genetic diseases common to Pennsylvania's Amish and Mennonite communities. These latest deaths are among those in an Amish community that has lost 21 babies in two generations.
In a sun-drenched laboratory in Phoenix, far away from bucolic Amish country, scientists at the Translational Genomics Research Institute analyzed tissue samples from four of the Amish babies and figured out what was happening. All of the babies who died had a mutation in a gene that regulates both genital and brain development, preventing a vital protein from developing and causing certain death.
Hereditary? Though the Amish parents knew their babies were likely to die, the deaths resembled sudden infant death syndrome, and the gene is one of a handful that scientists are now looking at to try to explain SIDS, commonly known as crib death. Babies who die from SIDS appear normal and healthy, then die suddenly, usually while they are sleeping.
In the past couple of years, scientists have become increasingly focused on the role of genetics in SIDS. Currently, SIDS is diagnosed when all other forms of death are ruled out, leaving families to wonder what went wrong. Previous research has identified risk factors--such as smoking cigarettes and putting infants to sleep on their stomachs--but has done little to get at the underlying cause. In the past decade, efforts to teach people about these risk factors, including the federal Back to Sleep campaign, have cut the number of SIDS deaths in half. Still, SIDS is the most common form of death for babies between 1 month and 1 year old, killing more than 2,200 infants annually. Researchers are now looking at genes as a way to explain why SIDS deaths continue even in the absence of risk factors.
Michael Ackerman, a pediatric cardiologist, is one of several SIDS researchers who have recently found abnormalities in the genes of SIDS babies that regulate the development of the autonomic nervous system, which governs basic functions like breathing, gasping, and the beating of the heart. "SIDS was a black box just a few years ago," he says, "and now it's like there is a candle lit."
Most researchers believe that genetic abnormalities bump babies into a high-risk group but that environment plays a role as well. Babies up to the age of 6 months are still developing their ability to control their bodies--even things we take for granted, such as breathing and swallowing. When an infant of that age has a genetic mutation that causes abnormal development, even if the baby looks and acts perfectly healthy, any small stress on the body, such as a prone sleeping position or blankets covering the baby's mouth, could cause sudden death.
But, for parents who have lost their children despite being careful, these theories offer little comfort. Kelly Del Vecchio, 34, says she was "obsessed" with preventing SIDS when she had her son, Ryan, in July 2003. He died three months and 12 days later. "We did everything right. We tried to do everything that they tell you to do," she says.
Not knowing why the baby died, she says, is one of the hardest things about SIDS deaths. "Your world's shattered, and when the doctors have nothing to tell you, there's just no reason for it," says Del Vecchio. "At least if the doctors had some cause, it would make a little more sense."
This story appears in the November 15, 2004 print edition of U.S. News & World Report.