Variants at Chromosome 17q21 Linked to Early Asthma
Variants are associated with increased risk, especially in children exposed to tobacco smoke
WEDNESDAY, Oct. 15 (HealthDay News) -- Variants at chromosome 17q21 are associated with an increased risk of early-onset asthma and interact with early-life exposure to environmental tobacco smoke, according to study findings published online Oct. 15 in the New England Journal of Medicine.
Emmanuelle Bouzigon, M.D., of INSERM Unite in Paris, France, and colleagues tested 36 single-nucleotide polymorphisms (SNPs) in the 17q21 region of 1,511 French subjects aged 7 to 65 with a family history of asthma.
The researchers found that 11 SNPs were associated with asthma, and observed the strongest associations for three of them: rs8069176, rs2305480 and rs4795400. They also found that four SNPs were significantly associated with the onset of asthma before age 4 but not with adult-onset asthma. The one with the strongest association -- rs8069176 -- was associated with a 2.9 times increased risk of early-onset asthma in the group exposed to environmental tobacco smoke.
"The novel findings relating to age and the role of early exposure to tobacco smoke will require replication by others before they are carved in stone. However, despite all this, the identity of the genes whose activity or function is modified by the causal variant is still unclear," state the authors of an accompanying editorial. "When more is known regarding the mechanism by which genetic variation at this locus alters susceptibility to asthma, ways to translate these findings into clinical practice may become more apparent."