Filaggrin mutations cause distinct pattern of eczema in children

The giant protein filaggrin has several vital functions in skin. People with mutated copies of the filaggrin gene (FLG) are at risk of developing eczema that begins earlier and is more severe than usual. A new population study by Danish scientists (published in the journal PLoS ONE) now shows that children with FLG mutations develop a distinct variety of eczema, with emphasis on exposed areas such as the cheeks and the backs of the hands.

The research, led by Hans Bisgaard at the University of Copenhagen, could in the future help doctors diagnose children at risk of developing eczema and design personalized treatment for them—including therapy that could change the course of the disease.

The researchers analyzed data from the Copenhagen Study on Asthma in Childhood, which comprised 411 children born to mothers with asthma and followed them over the course of seven years, with checkups every six months (or more often, if eczema flares warranted). The scientists tested DNA from the children, checking to see if they had one of the two most common FLG mutations, known as R501X and 2282del4.

The results were not as cleancut as one might like. Roughly 15% of the 170 children who developed eczema had FLG mutations. But so did 7% of the 212 children who did not develop eczema. So clearly having mutated FLG does not guarantee eczema, and there are other factors at work to compensate for the mutation or cause disease to develop even if you have good filaggrin.

The researchers found that, in general, short- and long-term symptoms of eczema were worse in children with mutated FLG; and the disease set in earlier and flares tended to cluster in certain areas, most importantly  the cheeks and backs of the hands.

What is your child’s eczema like? Or what was yours like as a child? Does it fit this pattern? I seem to remember it concentrated on the backs of my knees and the insides of my elbows. But over the years it has moved around a lot. Maybe we will see scientists develop a catalog of eczema subtypes caused by known mutations.