Dog owners ward off asthma against risk allele carriers

Among individuals carrying the 17q12-21 asthma-risk variant rs2305480, owning a dog appears to exert a protective effect against persistent wheeze, a recent study has found.

The researchers conducted a latent class analysis using data from five UK-based birth cohorts, yielding a cumulative sample size of 9,149 children. The primary outcome was the gene-environment interaction between the rs2305480 risk variant and owning a cat or dog in infancy.

In the overall study sample, the rs2305480 allele was associated with a nearly 40 percent increase in the likelihood of developing persistent wheezing, according to multinomial logistic regression analysis (additive model odds ratio [OR], 1.37, 95 percent confidence interval [CI], 1.25–1.51). In contrast, having owned a cat or a dog did not correlate significantly with wheeze risk.

Nevertheless, the researchers reported a statistically significant gene-environment interaction effect between the asthma risk allele and early life pet ownership, an effect that was significant in relation to dog ownership (p=8.3×10^–4).

In particular, in those who had owned a dog, the interaction between the rs2305480 risk allele and persistent wheeze was no longer significant (additive model OR, 0.95, 95 percent CI, 0.73–1.24). Meanwhile, children who had not owned pets saw an even greater risk estimate for persistent wheeze (OR, 1.61, 95 percent CI, 1.40–1.86). Cat owners saw no such dampening of wheeze likelihood.

“Future studies will be required to confirm the generalizability of the results in non-European populations with precise phenotyping,” the researchers said. “Furthermore, polygenic risk score approaches could be used to investigate the role of common environmental exposures on the development of asthma.”