Gene 'controls the first breath'

The gene controls babies' lung development

US scientists have identified the gene that controls a baby's first breath.

The Foxa2 gene controls others that allow foetal lungs to develop during pregnancy and function at birth.

Cincinnati Children's Hospital Medical Center experts say their research could lead to better treatments for premature babies with lung problems.

The Proceedings of the National Academy of Sciences study could also advance the treatment of children and adults with lung disorders, they say.

This will help us to identify genetic problems and develop new treatment approaches for lung disease in the future Dr Richard Russell, British Thoracic Society

Lungs do not fully mature until the last trimester of pregnancy, which is why babies can have breathing problems if they are born premature.

A premature baby's lungs often lack the necessary amount of surfactant - a chemical that prevents the tiny airways in the lungs from collapsing, which also allows the lungs to open when the newborn starts to breath after birth.

The absence of surfactant causes respiratory distress syndrome within hours of birth. Premature babies have to be given surfactant to keep the lungs working.

'Transition'

The researchers bred mice with and without the Foxa2 gene.

They found that the mice who did not have the gene developed all the signs and symptoms of respiratory distress syndrome on the first day of life and died within hours of birth.

The few that did survive went on to develop asthma-like symptoms and emphysema.

Knocking out the Foxa2 led to a related gene, Foxa1, being expressed more strongly. But this was not sufficient to support the development of sustainable healthy lungs in the mice.

However those mice who did have the Foxa2 gene survived normally.

The researchers concluded that Foxa2 controls key factors that allow the lungs of a foetus to develop fully and to breathe air when they are born.

Dr Jeffrey Whitsett, who led the research, said: "We showed that Foxa2 regulates a group of genes that stabilise surfactant production, which is required for the transition from the womb to breathing air and to protect the lungs from disease, bacterial infection and other disease and injury,"

He added: "It was surprising to us that a single gene was able to orchestrate so many other aspects of lung function we know are critical for survival at the time of birth.

"The discovery of this gene and understanding of how it works could lead to new treatments for premature infants and for children and adults who suffer from lung disease or injury."

Treatment approaches

Dr Richard Russell, of the British Thoracic Society, told BBC News Online: "Genetics is an exciting and vitally important area of respiratory medicine.

"Genetic research has already been carried out into lung diseases such as asthma and chronic obstructive pulmonary disease but more funding is needed for research so that we can discover how genetics can affect the lungs.

"This will help us to identify genetic problems and develop new treatment approaches for lung disease in the future."