The Eczema Gene That’s Kind of a Big Deal
As scientists learn more about skin-specific gene mutations, they are working to develop genetic testing that could ultimately help protect young children at risk.by Sarah Ellis Health Writer
Eczema (a.k.a. atopic dermatitis) isn’t rare—in fact, the National Eczema Association reports that over 31 million Americans are currently living with the skin condition. Though it usually begins in childhood, eczema can crop up at any time, causing itchy, dry skin that comes and goes in flares. It’s more severe in some people than others, but one thing is certain: It’s not exactly a walk in the park to deal with.
But now, scientific breakthroughs are revealing more about the genetic origins of eczema. An August 2020 study in Nature Communications found that two common mutations of the KIF3A gene are responsible for an impaired skin barrier, which can contribute to the development and onset of atopic dermatitis. “KIF3A is a gene that we found to be very important in determining skin barrier function in people,” says Gurjit Neeru Khurana Hershey, M.D., director of the Division of Asthma Research at Cincinnati Children's Hospital in Cincinnati, OH, and principal investigator on the study. “Individuals that carry common genetic variants in this gene had disrupted skin barrier function as evidenced by increased loss of water through their skin.” This promotes skin dehydration, which increases the odds that someone will start feeling that dreaded eczema itch.
Here’s why this genetic discovery is so huge: Identifying these genes early on could help doctors identify children at risk of developing eczema… and a whole host of related health problems like asthma and allergies later in life.
Eczema and Family History
The cause of eczema isn’t totally clear, but scientists know it has something to do with both nurture (external factors) and nature (family history). Research in the Expert Review of Clinical Immunology found evidence for several environmental risk factors, including personal care product use, air pollution, climate factors like heat and humidity, and even dietary choices.
If eczema runs in your family, your chance of getting it is significantly higher, with or without those external triggers. One possible reason: You've inherited certain genetic mutations from your parents. Jonathan Silverberg, M.D., associate professor of dermatology at The George Washington University School of Medicine and Health Sciences in Washington, D.C., notes that researchers had previously identified mutations of the Filaggrin (FLG) gene as playing a role in atopic dermatitis. The KIF3A gene (the one in this current study) was also previously associated with atopic dermatitis and allergic disease, but its role was not precisely understood.
“This study has several significant findings that bridge genetic associations to potential pathomechanisms of atopic dermatitis,” Dr. Silverberg says—meaning, the ways in which eczema starts occurring in the first place.
The Future of Screening
So, now you’re probably wondering… “OK, so what can I actually do with this information?” Though it doesn’t change anything right this instant, this finding could lead to better genetic testing to identify infants at high risk for eczema. And since half of people with moderate to severe eczema go on to develop asthma, hay fever, or food allergies, early detection would help doctors be on the lookout for—and proactively treat—these additional health complications. “I hope that testing for this genetic variation will help identify kids at risk for food allergy and asthma before they develop, so we can prevent disease onset or attenuate their disease,” Dr. Hershey says.
Unfortunately, prevention is a bit complicated. Dr. Silverberg explains that researchers have tried a variety of interventions aimed at preventing or mitigating eczema, including moisturizers, prebiotics, probiotics, and avoidance of external triggers like dust mites. “While individual studies showed possible benefits, none of these have conclusive evidence to support their recommendation in routine practice,” he says. “So, at this point, even if we could identify children at higher risk for atopic dermatitis, there isn’t that much we can do about it.”
Dr. Hershey hopes this new research will lead to specific treatment approaches that target the KIF3A gene. Ideally, scientists would discover a way to repair skin barrier function in infants before they have noticeable eczema symptoms—thereby stopping it before it starts.
If you or a loved one lives with eczema, you know how life-changing this breakthrough could be. “The psychosocial and mental health burden of atopic dermatitis can be improved tremendously simply by achieving tighter control of the signs and symptoms of atopic dermatitis,” Dr. Silverberg says. This isn’t the golden ticket (yet), but it’s one step closer to getting there.
Eczema Signs & Symptoms: National Eczema Association. (n.d.) “Eczema Causes and Triggers.” nationaleczema.org/eczema/
Genetic Mutation Study: Nature Communications. (2020.) “Disease-associated KIF3A variants alter gene methylation and expression impacting skin barrier and atopic dermatitis risk.” nature.com/articles/s41467-020-17895-x
Eczema External Triggers: Expert Review of Clinical Immunology. (2017.) “Environmental risk factors and their role in the management of atopic dermatitis.” ncbi.nlm.nih.gov/pmc/articles/PMC5216178/
Eczema Secondary Conditions: American Academy of Allergy, Asthma & Immunology. (n.d.) “Eczema (Atopic Dermatitis) Overview.” aaaai.org/conditions-and-treatments/library/allergy-library/eczema-atopic-dermatitis