Patients with asthma with certain genotype combinations demonstrate more intense symptoms when combined with a close proximity to roadways, suggesting that traffic-related air pollution exposure may affect the likelihood of asthma diagnosis and exacerbations, according to a recent published by Scientific Reports.

asthma symptoms The researchers examined the associations between single nucleotide polymorphisms (SNPs) and the combinations of SNPs in the toll-like receptor 4 (TLR) pathway, residential distance to roadway as a proxy for traffic-related air pollution exposure, and asthma diagnosis and exacerbations.

asthma treatment The study considered individual data on genotype, residential address, asthma diagnosis, and exacerbations from the Environmental Polymorphisms Registry. Patients were divided into 3 groups—hyper-responders, hypo-responders, and neither—and they measured the participants' distance between their residence and nearest major road.

Patients with certain genetic profiles had exhibited more intense symptoms following exposure to traffic pollution. Furthermore, patients with asthma who lacked this genetic profile did not have the same sensitivity to traffic pollution and do not experience worse asthma symptoms.

The authors emphasized that the results are based on genetic variation and in order to further understand this concept, people should think of human genes as written instructions for making proteins, according to a press release.

"All humans have the same genes, in other words the same basic instructions, but in some people one DNA base pair has been changed," co-lead author Shepherd Schurman, MD, associate medical director of the National Institute of Environmental Health Sciences (NIEHS) Clinical Research Unit, "This common type of genetic variation is called a single nucleotide polymorphism or SNP, and it can alter the way proteins are made and make individuals more or less prone to illness."