Variant Gene Increases Effect of Secondhand Smoke in Kids
Study finds that one-quarter of children have a variant that increases risk of respiratory illness
THURSDAY, Dec. 22 (HealthDay News) -- Children with a genetic variant of the tumor necrosis factor gene TNF-308 are especially susceptible to secondhand smoke and have an increased risk of developing respiratory illnesses that keep them home from school, according to a study in the Dec. 15 issue of the American Journal of Respiratory and Critical Care Medicine.
Frank D. Gilliland, M.D., Ph.D., and colleagues from Keck School of Medicine of the University of Southern California, Los Angeles, studied 1,351 fourth-graders in southern California. They performed DNA analysis using buccal cells and examined school absence reports.
The researchers determined that 324 (24%) of the children had one or more copies of the TNF-308 A variant. When such children were exposed to two or more household smokers, the investigators found they had more than a twofold risk (RR 2.13) of a school absence due to respiratory illness and more than a quadruple risk (RR 4.15) of a school absence due to lower respiratory illness compared to unexposed children homozygous for the more common TNF-308 G allele.
"Because of the high prevalence of secondhand smoke exposure and the adverse effects of secondhand smoke on respiratory illness, further research is warranted to identify genetically susceptible groups and to develop targeted interventions that reduce exposure among those at greatest risk for adverse events," the authors conclude.