By Matt Leingang
The Cincinnati Enquirer

Researchers at Cincinnati Children's Hospital Medical Center have identified a gene mutation that causes a severe and usually fatal lung disease in newborn babies.

The defective gene - called ABCA3 - disrupts the production of surfactant, a foamy fluid essential for the expansion of air sacs in the lungs.

Without surfactant, lungs cannot inflate, resulting in respiratory distress syndrome. About 24,764 infants in the United States - many of them premature babies - were born with respiratory distress syndrome in 2001, according to the American Lung Association.

Identifying the gene defect could lead to new medications for babies - before or after birth - that enhance their surfactant production, said Dr. Jeffrey Whitsett, a professor of pediatrics at Children's Hospital and co-author of a study that appears in this week's New England Journal of Medicine.

Symptoms of the respiratory disease include rapid breathing, nasal flaring, a grunting noise with each breath and blue around the lips, which indicates a lack of oxygen.

Whitsett worked with researchers at Johns Hopkins Children's Center and the National Cancer Institute's Laboratory of Genomic Diversity.

Surfactant has been a focus at Cincinnati Children's Hospital for two decades. In the 1990s, Children's experts played a leading role in developing and testing an artificial surfactant to improve the function of under-formed lungs in premature babies.

In this latest study, researchers looked at 21 infants with severe lung disease whose family medical histories suggested a genetic basis for their problems. Sixteen babies had the ABCA3 gene mutation, and of those, 15 died of their illness.

Whitsett cautioned that more research is needed. For example, the one infant with the ABCA3 mutation who survived his initial lung disease demonstrates that the defect may not always be fatal.

Furthermore, the gene defect was absent in two other infants who died - indicating that other genes are involved and have yet to be identified.

But the study offers a new insight into how the lung functions.

"As the causes of inherited disorders are increasingly understood, we all hope the knowledge gained from these studies will improve the lives of our patients and their families," Whitsett said.

E-mail mleingang@enquirer.com