SNPwatch gives you the latest news about research linking various traits and conditions to individual genetic variations. These studies are exciting because they offer a glimpse into how genetics may affect our bodies and health; but in most cases, more work is needed before this research can provide information of value to individuals. For that reason it is important to remember that like all information we provide, the studies we describe in SNPwatch are for research and educational purposes only. SNPwatch is not intended to be a substitute for professional medical advice; you should always seek the advice of your physician or other appropriate healthcare professional with any questions you may have regarding diagnosis, cure, treatment or prevention of any disease or other medical condition.
Although the itchy, red rashes that plague people with atopic dermatitis are usually set off by environmental irritants and allergens, the root of the condition (a type of eczema) is thought to be genetic.
A new report, published online this week in the journal Nature Genetics, shows that a DNA variation previously associated with Crohn’s disease may be one of the genetic risk factors for atopic dermatitis.
Researchers analyzed the genetic data of more than 3,500 people with atopic dermatitis and more than 4,900 controls from Germany, Poland and the Czech Republic. Their results showed that compared to people with two Cs at rs7927894, those with one T have 1.16 times the odds of having atopic dermatitis, while those with two Ts have 1.47 times increased odds.
The researchers estimate that 13% of the population with European ancestry has two Ts at rs7927894.
(23andMe customers can check their data at rs7927894 using the Browse Raw Data feature. Data for this SNP is available only to those customers who were typed on version 2 of our custom chip – i.e. customers who upgraded from version 1 or who received their data after September 1, 2008.)
A recent report associated rs7927894 with Crohn’s disease. In that study, each T increased the odds of Crohn’s by 1.16 times. The authors of the current atopic dermatitis study note that Crohn’s and atopic dermatitis share several features – recurrent bouts of inflammation, cells that fail to form proper barriers (in the intestine and skin, respectively) and deficient immune responses against bacterial infections. They suggest that the association of rs7927894 with both conditions may explain why there is a high incidence of eczema in people with Crohn’s disease.