An international team of scientists, led by researchers in Australia, found more than a hundred different genetic variants in or near immune-related genes that are associated with having asthma, hay fever and eczema.
In a study published this week in Nature Genetics, researchers at the QIMR Berghofer Medical Research Institute in Brisbane Australia— and about a dozen other institutions around the world including 23andMe — identified new genomic regions associated with these three allergic diseases providing a deeper understanding about why these conditions often occur together in an individual.
Led by Manuel Ferreira, Ph.D, the study was three times larger than the next largest genome wide associations of allergic disease. This study also stands out because it didn’t focus on just one condition, looking instead at the overlapping genetic influences for these three conditions, which tend to occur together.
“Asthma, hay fever and eczema are allergic diseases that affect different parts of the body: the lungs, the nose and the skin,” Ferreira said. “We already knew that they were similar at many levels. For example, we knew that the three diseases shared many genetic risk factors. What we didn’t know was exactly where in the genome those shared genetic risk factors were located.”
By dramatically increasing the size of the study and focusing on three overlapping conditions, the researchers substantially improved their ability to identify shared risk variants.
The scientists looked at data from more than 360,000 people — including data from about 118,000 23andMe customers who consented to participate in research as well as data from institutions in the UK, Germany, the Netherlands and Australia. Their analysis identified more than 130 different genes or gene regions associated with allergic disease, with the vast majority involved in immune response. This, in turn, explains why these conditions often occur together.
“Our genetic findings demonstrate that asthma, hay fever, and eczema co-occur to a large extent because they share genetic risk variants that dis-regulate the expression of immune-related genes,” the researchers concluded in their paper.
The majority of genes and gene regions identified influence the function of immune cells. The genetic variants identified in the study disrupt the function of genes involved in immune response, in essence turning them off.
Beyond identifying the different genes involved and explaining why these conditions occur together, the study also helped identify potential new treatments for therapy.
“Importantly, we have identified several drugs that we believe could be targeted at some of these genes to treat allergies,” Ferreira said. “The first step would be to test those drugs in the laboratory.”
