Two Genes Lined to Asthma Susceptibility

BY MARY ANN MOON
Elsevier Global Medical News

Researchers have identified a genetic locus on chromosome 1q31 that is significantly associated with susceptibility to asthma, according to a study published online in the New England Journal of Medicine.

Two candidate genes at this locus were identified in a genomewide association study of North American children of European ancestry, and the findings were replicated in European adults and in North American children of African ancestry, said Patrick M. A. Sleiman, Ph.D., of Children’s Hospital at Philadelphia’s Center for Applied Genomics and his associates (N. Engl. J. Med. 2009 Dec. 23 [doi:10.1056/NEJMoa0901867]).

The researchers first performed a genomewide association study in 793 children (mean age 7 years) with moderate to severe asthma requiring daily steroid therapy. Controls consisted of 1,988 nonasthmatic children. All the children were Americans of European ancestry.

Eight single-nucleotide polymorphisms (SNPs) were found to be significantly associated with asthma. All of these SNPs mapped to the DENND1B gene or the CRB1 gene at a novel locus on chromosome 1q31. The findings were then replicated in a Northern European cohort of 917 adults who had childhoodonset asthma and 1,546 control subjects.

A cohort of 1,667 African American children with asthma and 2,045 African American children without asthma was then assessed. Again, each of the eight SNPs on chromosome 1q31 was strongly associated with asthma.

The study was supported by an award from the Children’s Hospital of Philadelphia, and grants from the state of Pennsylvania, the Lundbeck Foundation, and the National Institutes of Health. No conflicts of interest were reported.