Allergies: Genetics and Your Risk
Of all the things your parents can do for you, handing down allergies isn’t the greatest.
Allergies are annoying (and sometimes life-threatening) reactions the body has to harmless substances, such as pollen or peanuts. They occur when your immune system interprets the proteins of those allergens as a threat to the body. The body reacts as it would to bacteria or a virus but often more vigorously.
Research on allergies hasn’t definitively shown why the body has this reaction. However, it does show that allergies share a genetic link. That means parents can pass them down to their children.
While allergic reactions do share a genetic link, specific allergies do not. If your parents both had seasonal allergies, you may have a higher risk of developing them too. This doesn’t mean you’ll have the same allergy, however. Your body will be more likely to have allergic reactions, but it could be to peanuts, shellfish, or other common allergens.
Father-Son, Mother-Daughter Connection
A study published in the Journal of Allergy and Clinical Immunology found a gender-specific genetic link in inherited allergies. The study found that mothers who had eczema, an allergic skin disease, were 50 percent more likely to have a daughter with eczema. The same was true with fathers and sons.
Clinicians at the Southampton University Hospital Foundation Trust in Hampshire, United Kingdom conducted the study. It assessed 1,456 23-year-old patients. Besides the eczema connection, they found that the risk of asthma in boys doubled if the father had asthma, but not if the mother did (HSJ, 2012).
Scientists have made significant discoveries regarding other factors that contribute to how allergies affect family members.
For instance, one study looked at allergies as they related to fraternal and identical twins. In those studied, researchers found that seven percent of fraternal twin pairs would share a peanut allergy. However, 64 percent of identical twins would have the same allergy. This affirmed the link between allergies and genetics, because identical twins share the exact same DNA. Fraternal twins only share about half of the 25,000 genes in DNA.
However, although family members share genes, they also share living spaces and similar eating habits. This can affect allergies. For example, one study showed that a mother’s eating habits could affect a child’s potential for peanut allergies.
According to the study, published in the journal Pediatrics, if a mother eats peanuts while pregnant, the risk of the child developing a peanut allergy can quadruple. The study found that if she eats peanuts while breastfeeding, the child’s risks double. However, evidence shows that if a pregnant mother avoids peanuts during pregnancy, it does nothing to decrease a child’s risk of a peanut allergy (Pediatrics, 2008).
What You Can Do
Talk to your doctor if your parents have allergies—even if you aren’t showing symptoms. This could help prevent future complications, such as an allergic reaction to drugs you may be unaware of.
If you notice the start of allergy symptoms, you may be able to begin immunotherapy treatments earlier. Immunotherapy uses a series of shots spread out over three to five years. The shots contain extracts from allergens to help the body become acclimated to the allergen. This helps to prevent allergic reactions.
If you have allergies and you’re concerned about your child, talk to his or her pediatrician. The doctor can explain potential allergies your child may develop and what you can do about them.