Researchers have identified a genetic locus on chromosome 1q31 that is significantly associated with susceptibility to asthma.
Two candidate genes at this locus were identified in a genome-wide association study of North American children of European ancestry, and the findings were replicated in a cohort of European adults and a population of 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 [doi:10.1056/NEJMoa0901867
The researchers first performed a genome-wide association study in a cohort of 793 children (mean age 7 years) who had moderate to severe asthma requiring daily cortico-steroid therapy. A control group of 1,988 nonasthmatic children also was assessed. All the children were Americans of European ancestry.
Eight single-nucleotide polymorphisms (SNPs) were found to be significantly associated with asthma. All mapped to the DENND1B gene or the CRB1 gene at a novel locus on chromosome 1q31. The findings were replicated in a European cohort of 917 adults with childhood-onset 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.