NEW YORK – Genetic loci implicated in diseases ranging from hair disorders to hormone-related conditions appear to coincide with susceptibility to the skin condition acne vulgaris, according to new research by investigators at King's College London, St. John's Institute of Dermatology, the QIMR Berghofer Medical Research Institute, and elsewhere.
"We know that the causes of acne are complicated, with a mix of biological factors such as genetics and hormones, and environmental factors," senior author Michael Smith, head of King's College London's Genomic Medicine Group, said in a statement. "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."
In a study published in Nature Communications on Monday, Smith and his colleagues presented findings from a genome-wide association study and meta-analysis involving 20,165 individuals of European ancestry with acne and 595,231 without. From these cases and controls, they tracked down more than two dozen new and 14 known variants with ties to acne.
"As well as suffering from the symptoms of acne, individuals describe consequent profound, negative impacts on their psychological and social wellbeing," co-author Catherine Smith, a professor of dermatology and therapeutics at King's College London, said in a statement. "It's exciting that this work opens up potential avenues to find treatments for them."
The team tapped into the risk variant collection and a handful of other variants found in past GWAS to come up with a polygenic risk score for acne. In another 2,058 individuals with a self-reported acne history, the risk score appeared to explain nearly 6 percent of acne heritability, suggesting that a considerable proportion of the condition's heritability may fall in yet-to-be-detected parts of the genome.
"Individuals reporting moderate or severe acne had significantly higher mean acne PRSs than those that reported no acne," the authors reported, adding that "the acne PRS has the greatest predictive ability in individuals with severe acne."
When the team used fine-mapping, expression quantitative trait locus-based analyses, and other approaches to characterize the regulatory regions and genes coinciding with 29 newly-detected risk variants, meanwhile, it saw suspected causal sites with ties to hair follicle features and Mendelian conditions such as ectodermal dysplasia or pustular psoriasis.
The findings also pointed to potential genetic overlap between acne vulgaris and hormone levels, hormone-responsive breast cancer and other hormone-sensitive cancers, immune-related conditions, chronic pain, and psychiatric traits.
The authors noted that these and other findings from the study "represent a transformational increase in our understanding of the genetic basis of acne." Even so, they cautioned that the risk variants identified did not encompass loci previously linked to the skin condition in individuals of Han Chinese ancestry, pointing to "potential differences in the genetic architecture of acne between different ethnic populations."