The first major gene location responsible for a severe, often painful type of food allergy called eosinophilic esophagitis (EoE) has been identified by scientists.
In this disease, which may cause weight loss, vomiting, heartburn and swallowing difficulties, a patient may be unable to eat a wide variety of foods.
After conducting a genome-wide association study, study leader Hakon Hakonarson, director of the Center for Applied Genomics at The Children's Hospital of Philadelphia, and colleagues found that EoE was linked to a region of chromosome 5 that includes two genes.
The likely culprit is the gene TSLP, which has higher activity levels in children with EoE compared to healthy subjects.
In addition, TSLP has been previously linked to allergic inflammatory diseases, such as asthma and the skin inflammation, atopic dermatitis.
"This gene is a plausible candidate because of its biological role in allergic inflammation," Hakonarson said.
Only recently recognized as a distinct condition, EoE, like other allergies, has been increasing over the past 20 years, and its reported incidence of one in 10,000 people may be an underestimate.
The hallmark of EoE is swelling and inflammation in the esophagus, accompanied by high levels of immune cells called eosinophils.
It can affect people of any age, but is more common among young men who have a history of other allergic diseases such as asthma and eczema. EoE is often first discovered in children with feeding difficulties and failure to thrive.
The study appears online today in Nature Genetics.