WASHINGTON (Reuters) - Mutations in genes involved in the development of the autonomic nervous system may help explain why some infants still succumb to sudden infant death syndrome despite education campaigns that have cut the rate in half, and why black infants are more at risk than other U.S. groups, researchers report.
Dr. Debra Weese-Mayer, of Rush University Medical Center in Chicago, said the finding does not fully explain the unexpected deaths of 3,000 U.S. infants each year, but helps explain some of the underlying biology.
“For years everyone said SIDS was a mystery, but to me it is a puzzle and each of our studies fits in another piece,” Dr. Weese-Mayer said in a telephone interview. “This is one more critical piece of information that tells us we are on the right path.”
As reported in the September issue of Pediatric Research, Dr. Weese-Mayer and colleagues at the University of Pittsburgh and elsewhere, compared DNA obtained from brain specimens from 92 SIDS cases to that derived from blood samples from 92 healthy 1-year-olds.
The researchers looked specifically at genes “pertinent to early embryologic development of the autonomic system.”
They found 11 different protein-modifying mutations in these genes in 14 of the 92 SIDS cases but only one mutation - the same one - in two of the 92 healthy infants.
“The curiosity is that 71% of the SIDS cases that had the mutation were African-American and both controls (that had it) were African-American,” Dr. Weese-Mayer said. “Knowing that the SIDS incidence is significantly higher in African-Americans gives strong support for the possibility of a genetic basis.”
Other researchers have found different genes that may be involved in SIDS.
In July a team at the Translational Genomics Research Institute in Phoenix, Arizona, found a new genetic disorder in Amish families from Pennsylvania that is associated with sudden infant death and sometimes malformation of the genitals.
In 2000 and 2001 researchers in the United States and Japan found a role for the serotonin transporter gene promoter in the brainstems of SIDS victims.
The tissue from the SIDS babies was donated anonymously, so Dr. Weese-Mayer says she cannot tell if the gene mutations her team found run in families. She hopes the government might sponsor a large study to see how common the genetic mutations are in the population as a whole, to help determine whether the mutations actually cause SIDS.
Source: SOURCE: Pediatric Research, August 2004. [ Google search on this article ]
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