A study, reported in the New England Journal
of Medicine (October 21, 2004), showed
that individuals with a form of a particular
gene might be protected from developing
asthma. Individuals missing this particular
gene variant have increased odds of developing
the breathing disorder. Prostaglandin
is one of the chemicals that cause inflammation
and contribute to the narrowing of
the airways during an asthma episode.
Prostaglandin needs a receptor, PTGDR, to
work. The gene in question has this receptor.
The study examined variants in genes of
518 Caucasian patients and 80 African
Americans. The data were then compared
with information from 175 Caucasian and
45 African American individuals without
asthma. The researchers discovered that the
participants with asthma were only about
half as likely to have the gene variant.
"If you have this protective form of the
gene, you have half the asthma risk," said
study author Craig M. Lilly, MD. He added
that drugs to block the receptor are getting
ready to enter clinical trials. "They were
developed for asthma and allergic rhinitis
and are just being tested in humans. These
drugs block prostaglandin D2, which is one
of the substances that narrows the airways
in acute asthma."