Gene Variant Acts as Shield

A study, reported in the New England Journalof Medicine (October 21, 2004), showedthat individuals with a form of a particulargene might be protected from developingasthma. Individuals missing this particulargene variant have increased odds of developingthe breathing disorder. Prostaglandinis one of the chemicals that cause inflammationand contribute to the narrowing ofthe airways during an asthma episode.Prostaglandin needs a receptor, PTGDR, towork. The gene in question has this receptor.

The study examined variants in genes of518 Caucasian patients and 80 AfricanAmericans. The data were then comparedwith information from 175 Caucasian and45 African American individuals withoutasthma. The researchers discovered that theparticipants with asthma were only abouthalf as likely to have the gene variant.

"If you have this protective form of thegene, you have half the asthma risk," saidstudy author Craig M. Lilly, MD. He addedthat drugs to block the receptor are gettingready to enter clinical trials. "They weredeveloped for asthma and allergic rhinitisand are just being tested in humans. Thesedrugs block prostaglandin D2, which is oneof the substances that narrows the airwaysin acute asthma."