A recent study analyzing the genetic data of thousands of rosacea patients has pinpointed seven genomic regions potentially associated with rosacea symptom severity.1 This builds off information gathered in a similar study funded by the NRS, which identified two genetic loci, or specific regions on chromosomes, linked to rosacea.2 These are some of the first genome-wide association studies on rosacea, an exciting area of research which could lead to the identification of potential new pathways for treatment.
In the new study published in Human Molecular Genetics, researchers used data from the personal genomics company 23andMe to gather information from a study group of 73,265 individuals of European ancestry who self-diagnosed with rosacea.1 In addition to the genetic data, participants filled out a uestionnaire on rosacea symptom severity. The genome-wide analysis found that variants in seven genetic regions showed a significant association with rosacea symptom severity. Of the seven loci, two had previously been genetically associated with skin pigmentation, two with inflammatory autoimmune disease, and one associated with both. Two loci didn’t contain any obvious candidate genes for rosacea.
One of the loci linked to rosacea is also associated with a variant thought to be related to inflammatory bowel disease. Because of the overlap between the loci for immune mechanisms and skin pigmentation, the researchers investigated correlations between rosacea symptom severity and relevant conditions for which genome-wide association studies were available. Although there was no genome-wide data available for pigmentation, they found positive correlations between rosacea symptom severity and inflammatory bowel disease and ulcerative colitis. The NRS has reported on past population-based studies showing associations between rosacea and ulcerative colitis and Crohn’s disease, but cause and effect still need to be demonstrated.
The results of the study suggest that both skin type and inflammatory mechanisms are part of the underlying disease process of rosacea, although the results require further study with patients with a confirmed diagnosis. Future research may focus on the variants within these genetic loci to identify potential therapeutic targets.
1. Aponte JL, Chiano MH, Yerges-Armstrong LM, et al. Assessment of rosacea symptom severity by genome-wide association study and expression analysis highlights immuno-inflammatory and skin pigmentation genes. Hum Mol Genet 2018 May 16. Doi: 10.1093/hmg/ddy184. [Epub ahead of print]
2. Chang AL, Chung PI, Chen YJ, et al. Assessment of the genetic basis of rosacea by genome-wide association study. J Invest Dermatol 2015;135:1548-1555.