A genome-wide association study (GWAS) of acne has identified 29 regions of the genome that influence the condition.
Acne vulgaris is a common skin disorder. It is the result of inflammation of the pilosebaceous unit (hair follicles and their accompanying sebaceous gland). It leads to the formation of comedones, papules, pustules, nodules and cysts. Typically, lesions are restricted to the face, neck, chest and back.
Acne is the most prevalent skin disease worldwide. In 2019, acne was responsible for nearly 5 million disability-adjusted life years (DALYs) globally. This is greater than other chronic inflammatory conditions. Additionally, acne is associated with impaired quality of life, reduced school and work performance and a significant impact on mental health. Individuals with acne have increased rates of depression and higher rates of mental illness than those without acne.
Although there have been advances in new treatments for other inflammatory skin diseases, including psoriasis and atopic dermatitis, there is still an unmet need for acne treatment. Early intervention strategies are key to avoid unnecessary scarring. The most effective agent to treat acne is isotretinoin but this is associated with a significant side effect profile.
Several twin studies have demonstrated a genetic contribution to acne susceptibility. Heritability estimates are around 80%. Other molecular genetic studies have identified genomic loci harbouring alleles associated with disease. Funcional characterisation of these signals has identified genes involved in the development and maintenance of the hair follicle and wound healing.
A meta-analysis of GWAS of acne
In a recent study, published in Nature Communications, researchers aimed to further characterise the genetic architecture of acne vulgaris and identify additional genomic loci that contribute to disease susceptibility. The team specifically performed a meta-analysis of GWAS of acne from nine cohorts. This comprised of 615,396 study participants (20,165 cases and 595,231 controls).
The study identified 29 new genetic variants that were more common in people with acne. The team also confirmed 14 of 17 variants that were already known to be associated with the condition. This brings the total number of reported variants to 46. In addition, a number of the loci identified have previously been implicated in other skin and hair conditions.
Finally, the team explored the potential for a polygenic risk score that estimates an individual’s genetic liability to predict phenotype expression. They found that individuals with the highest genetic risk were more likely to have severe disease.
Professor Michael Simpson (Head of the Genomic Medicine Group, King’s College London) said:
“We know that the causes of acne are complicated, with a mix of biological factors such as genetics and hormones, and environmental factors. Understanding the genetics of the condition will help us to disentangle some of these causes and find the best way to treat the condition. This is a really promising area for further study and opens up a lot of avenues for research.”
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