Study Uncovers 2 Gene Loci Linked to African Ancestry and Eczema Risk
Research By: Tesfaye Mersha, PhD
Post Date: December 24, 2024 | Publish Date: Sept. 7, 2024
Nearly everyone involved in population-scale health research is aware of the well-documented access, treatment, and outcome gaps between Black and white Americans.
Often, closer examination of such gaps suggests that differences are less about race and more about systemic racism and environmental exposures. Additionally, scientists find meaningful genetic variations among different populations experiencing a similar disease but exposed to different environmental, lifestyle, and social determinants of health.
Now, experts at Cincinnati Children’s report finding two ancestry-specific gene loci that affect atopic dermatitis (AD) susceptibility among people with African ancestry. Findings were published in September 2024 in HGG Advances.
Much More Than Itchy Skin
Atopic dermatitis, also known as eczema, is a chronic itchy inflammatory disease of the skin. An estimated 31.6 million people (10.1%) in the U.S. have some form of eczema, with prevalence peaking during early childhood, according to the National Eczema Association. Beyond the often-unbearable itch that flare-ups can cause, more than 50% of children with severe AD later develop asthma. Young children with AD are also six times more likely to develop food allergies.
While the condition affects many populations, most genetic research into risk factors has involved samples from European and East Asian people. The new analysis involved more than 1,700 biological samples provided by African Americans, including more than 700 people with AD.
Two New Clues
By applying admixture mapping (a special type of genetic data analysis developed for admixed populations, including African Americans), genome-wide association analysis, and joint (both admixture and association) analysis approaches, the study identified two loci: rs2195989, located in the gene ANGPT1 (8q23.1), and rs62538818, found in the intergenic region between genes LURAP1L and MPDZ (9p23).
“These variants were not discovered using European populations, underscoring that without diverse representation, genomics research may miss critical insights, potentially leading to health disparities,” says corresponding author Tesfaye Mersha, PhD, who leads the Population Genetics, Ancestry, and Bioinformatics Laboratory at Cincinnati Children’s.
Knowing more about the gene variants involved in AD can help scientists better understand which treatments will work best for different populations and under different environmental conditions—offering a road map to precision medicine, Mersha says. He argues that the lack of ancestral diversity limits the understanding of the genetic factors influencing diseases worldwide.
“Our findings advocate for more inclusive genomics research to ensure equitable healthcare advancements. Much more research lies ahead to translate these genetic findings into more fine-tuned AD care. Likewise, similar ancestry-specific studies are needed for many more diseases.”
About the Study
Yadu Gautam, PhD, Division of Asthma Research, was the first author of the study. Co-authors also included experts from the divisions of Human Genetics and Allergy and Immunology. Funding sources included two grants from the National Institutes of Health (R01 HG011411 and U19AI070235).
More news from the Mersha Lab:
- Listen to a conversation on NPR about under-diagnosed asthma in Africa
- Read an interview featured in the “Multi-Omics Playbook 2024” issue published by Front Line Genomics
| Original title: | Joint genotype and ancestry analysis identify novel loci associated with atopic dermatitis in African American population |
| Published in: | HGG Advances |
| Publish date: | Sept. 7, 2024 |
Research By
My research combines genetic ancestry, bioinformatics, and statistical and functional genomics to unravel genetic and non-genetic contributions to complex diseases in human populations, particularly in allergic disorders.
