Do allergies such as hay fever, asthma and eczema arise more from allergy genetics or environmental factors? It’s commonly accepted that these conditions are derived from a combination of the two, scientists are now trying to find out more about which actual genes are responsible for causing allergic misery.
Millions of allergy sufferers endure a variety of unpleasant allergy symptoms ranging from relatively harmless (but irritating) sneezing to extreme fatigue, skin conditions and severe asthma.
Recently, an international research team studying allergy genetics identified a series of ten genetic variants that are linked to an increased chance of the development of allergies and/or asthma; published by Nature Genetics, the study indicated that the more of these variants associated with a given person, the more likely that person is to develop an allergy or a similar condition. So, are are allergies genetic? Yes, it’s likely that there is a genetic component.
The Onset of Allergies
Studies have shown that throughout Australia and New Zealand, an estimated 30% of children have some sort of allergy; allergies occur when the immune system perceives some level of threat from an otherwise harmless substance such as pollen, which are known as allergens.
When the B lymphocyte cells in the human immune system reacts to this perceived threat by producing antibodies against the allergen in question, an allergy develops; in the human body this normally happens at a very young age and is called ‘sensitization’, which means that the body becomes sensitive to a particular substance.
Going forward, exposure to that allergen causes the antibodies to bind to the allergen, which then causes a variety of reactions that ultimately end up with symptoms such as red, inflamed skin as in the case of eczema, or problems with stuffy nose and/or asthma.
Statistics indicate that one fifth of Australians and New Zealanders will develop the symptoms of eczema at some point in their lives; the numbers are the same for those who suffer from hay fever and one in ten report suffering from a serious respiratory condition such as asthma, which can lead to further complications and even death.
Interestingly, it has been found that approximately 80% of people living with asthma also suffer from a second condition such as hay fever and/or eczema.
Allergy Genetics: Nature vs. Nurture?
There are a number of genes involved in the body’s sensitization to any given allergen; one way to develop such issues is to be passed ‘faulty’ genes from previous generations such as your parents; inheriting enough of these genes will not only ensure that you’re sensitized to an allergen as a child, it will also ensure that you develop other conditions such as hay fever or asthma later in life.
In a recent allergy study, which involved 12,000 people who suffered from allergies compared with 20, 000 people who did not, researchers were able to discern 10 regions of DNA that differed between those with and those without.
What’s Next for Research Into the Genetics of Allergies?
Going forward, further research will focus on identifying still more regions of DNA that play a part in the development of allergies; as for the ten regions identified to date, there are further research opportunities available as far as identifying why faulty versions of the genes increase allergy risks.
While it’s assumed that there are specific factors involved on an environmental level, new studies will be set up to determine what role they play in setting off the faulty genes and understanding how these genes play a role in the development of allergies and asthma.
If you’re over 18 and have asthma, you can help researchers by joining the largest study into asthma genetics.
Allergy Genetics References:
Henderson, A. J., Gupta, R., Husemoen, L. L., Dharmage, S. C., Hartikainen, A., Montgomery, G. W., et al. (2013). Meta-analysis of genome-wide association studies identifies ten loci influencing allergic sensitization. Nature Genetics, 45(8), 902-906.