The study – done by scientists here at 23andMe and researchers at the University of Bristol’s Avon Longitudinal Study of Parents and Children (ALSPAC) in the UK – is the largest genome-wide association study ever conducted on common allergies with data from more than 53,000 people.
“Although environmental factors certainly play a role, our study reinforces the genetic link between common allergens and a person’s susceptibility to experiencing an allergic reaction,” said David Hinds, Ph.D., author and 23andMe principal scientist.
Asthma and allergies, which are strongly linked to each other, are among the most common diseases in the industrialized world.
The last two decades has seen a surge in the number of people with asthma and allergies. There are many theories offered to explain this including the “hygiene hypothesis,” which suggests that an increasingly sanitized environment inhibits the development of the immune system. Another theory is that increasing exposure to chemicals and pollutants are the culprit.
People with allergies tend to be allergic to multiple things.Sometimes this makes sense – being allergic to cats and dogs for instance – other times the groupings make you scratch your head. Based on our research survey data, we found that if you are allergic to one insect’s sting, it is more likely that you’ll be allergic to another. But food allergies do not appear to be associated with other kinds of allergies.You can learn more about these associations here.
But whatever the environmental factors, genetics plays a very important role in whether or not an individual develops asthma or allergies. So understanding the genetic underpinnings of both conditions can offer insight not just in who may develop asthma or allergies but also into the biological pathways for the conditions. This can help in identifying potential new treatments for the conditions.
This study looked at common allergies, including allergies to pollen, dust-mites and cats. The researchers found 16 new genetic associations with allergies, eight of which have also been associated with asthma. While the link between the development of allergies and asthma is well established, these new genetic variants add to our understanding of the connection between these conditions.
To do the study, 23andMe selected self-reported data on allergies for pollen, dust-mites and cats. The Avon Longitudinal Study of Parents and Children had comparable data. The researchers then used this combined data as part of the genome-wide association meta-analysis.
“Allergy is an important component of many diseases, including asthma, eczema and hay fever, which together account for a huge burden on patients and the health services.” said professor John Henderson of ALSPAC. “This is a very exciting time for allergy research. Genetic discoveries have identified specific pathways of allergy development that are not shared with allergic diseases like asthma. Understanding these pathways could lead to eventual development of drugs that cure or prevent allergy rather than just suppressing its symptoms.”