Asthma: Is It All in the Genes?
A new study by researchers at Cincinnati Children’s has identified which children – based on their genetic makeup – might be most susceptible to environmental triggers for asthma.
The study shows that children with a particular form of gene are more likely to have persistent wheezing if exposed to diesel exhaust, environmental tobacco smoke or mold by 24 months of age. The study, published online in the Journal of Pediatrics, investigates the interplay between genes and multiple environmental factors on wheezing in early childhood.
Understanding the factors that contribute to persistent wheezing in early childhood is an important step in advancing our understanding of asthma, says Gurjit Khurana Hershey, MD, PhD, director of asthma research at Cincinnati Children’s and senior author of the study.
"Our study provides evidence that high levels of environmental exposures in children increased their risk of wheezing at 12 months and 24 months – but only in children with the GST-P1 Val105 polymorphism, whose link to asthma is well known," she says.
Asthma is a complex heritable disease: There are a number of genes that contribute to a person's susceptibility, and chromosomes five, six, 11, 14 and 12 have all been implicated. GST-P1 Val105 is located on chromosome 11, a known "hot spot" for asthma-related genes.
"The lung undergoes critical development in infancy and early childhood, and this is the time that asthma symptoms are beginning to develop. Early exposure to diesel exhaust likely has direct effects on lung development and inflammation, some of which may be longlasting," explains Dr. Hershey. "Early childhood wheezing and early persistent wheezing may be a precursor to asthma in these children. The study supports that the GST-P1 genotype may add clinical value to the evaluation of asthma and wheezing in young children exposed to high levels of diesel exhaust particles, environmental tobacco smoke or visible mold in the home."
