Peanut Allergy May Be about Genes as Much as Exposure
Canadian researchers have shed more light on what causes peanut allergy, pinpointing a specific gene behind the often life-threatening sensitivity and offering further evidence that genetics as well as environment play a role in the development of food allergies.
The gene, called c11orf30/EMSY (EMSY), is already known to play a role in other allergy-related conditions, such as eczema, asthma, and allergic rhinitis. This study is the first to associate the EMSY locus with food allergy, and these findings suggest that the gene plays an important role in the development of not just food or environmental allergy, but a general allergic predisposition.
“Food allergy is the result of both genetic and environmental factors, but there are surprisingly few data regarding the genetic basis of this condition,” said study leader Dr. Denise Daley, a Tier II Canada Research Chair at St. Paul’s Hospital, Vancouver, BC, in the genetic epidemiology of common complex diseases. “The discovery of this genetic link gives us a fuller picture of the causes of food allergies, and this could eventually help doctors identify children at risk.”
Peanut allergy develops in early life and is rarely outgrown; the symptoms can be severe and even life threatening.
For their study, published in the Journal of Allergy and Clinical Immunology, the researchers from The Allergy, Genes and Environment Network (AllerGen) analyzed DNA from 850 individuals with a peanut allergy recruited from the Canadian Peanut Allergy Registry (CanPAR) and nearly 1,000 individuals without a peanut allergy. The team scanned over 7.5 million genetic markers across the DNA through a genome-wide association study (GWAS) searching for clues as to which genes might contribute to an increased risk of developing food allergies. The team also analyzed results from six other genetic studies from American, Australian, German and Dutch populations.
What they found was that EMSY was associated with an increased risk of both peanut allergy and food allergy, and five other gene locations are also suspected to be involved.
Earlier this year, groups like AAP, WHO and others, overturned their peanut allergy guidelines, advising pregnant women to no longer eliminate peanuts from their diet, and calling for limited dietary introduction of peanuts as early as four to six months for babies considered ‘at risk’. While the findings from this study are not expected to change those guidelines, they may may help pediatricians better identify and guide at-risk children.
“One of the hurdles in developing new treatments for food allergies is identifying the specific genes and pathways we need to target,” adds Dr. Aida Eslami, a co-first author of the study and postdoctoral fellow at The University of British Columbia. “These results suggest that EMSY could be a useful target for predicting and managing food allergy treatments in the future.”