Patchy hair loss caused by the immune system attacking hair follicles directly — a different disease from male-pattern baldness despite the shared word "alopecia." About a 2% lifetime risk, usually starting before age 30, affecting men and women alike. The two variants here come from a 2015 meta-analysis that resolved the field's long-known HLA signal and found two loci beyond it.
Alopecia areata is an autoimmune disease: the immune system attacks hair follicles directly, causing sudden patchy hair loss, usually on the scalp. In most people it stays patchy and often regrows on its own or with treatment. In a minority it progresses further — to total scalp hair loss (alopecia totalis) or total body hair loss (alopecia universalis). It affects roughly 2% of people at some point in their lives, most often starting before age 30, and affects men and women alike.
This is a genetically distinct condition from male-pattern baldness, which is androgen-driven rather than autoimmune. They share a word, not a mechanism.
The disease's strongest and longest-known genetic signal sits in the HLA region — the part of the genome that shapes how the immune system recognises what belongs to the body and what does not — established by Petukhova et al. 2010, the first genome-wide study of the disease. That study's title states the finding plainly: alopecia areata "implicates both innate and adaptive immunity."
Betz et al. 2015 returned to the question with a larger meta-analysis, and its title says exactly what it accomplished: it "resolves HLA associations and reveals two new susceptibility loci." Those two new loci — ACOXL and PRDX5 — are the variants on this page. Neither gene has an established, well-understood role in autoimmune attack on hair follicles; they are reported here as statistically real findings from a solid study, not as a mechanism this page can explain.
The HLA region itself is not represented here. HLA associations are usually reported as haplotypes across several linked positions rather than a single two-allele variant, and this site's collector only accepts clean biallelic records — the same reason other conditions on this site sometimes carry a weaker signal instead of the field's strongest one. That is a limit of what this page can show, not a claim that HLA does not matter; it is, by a wide margin, the most established genetic factor in this disease.
Alopecia areata is diagnosed by physical examination of the hair loss pattern, sometimes with a scalp biopsy — not by genotype. Treatments include corticosteroid injections, topical or oral immunotherapy, and newer JAK-inhibitor drugs for more extensive cases, chosen by a dermatologist based on how much hair is affected and how the disease is progressing. Nothing on this page changes that.
Both variants here are statistically real findings from a genome-wide meta-analysis, not established causal mechanisms. Neither ACOXL nor PRDX5 has a settled biological story connecting it to autoimmune attack on hair follicles — the paper reports them as new susceptibility loci and leaves the mechanism for future work, and this page does the same rather than inventing one.
Androgenetic alopecia (male-pattern baldness) shares the word "alopecia" and nothing else genetically — it is androgen-driven hair thinning, not an autoimmune attack, and is catalogued separately for that reason.
What a 23andMe/AncestryDNA export or raw VCF can and can't tell you about Alopecia Areata comes down to these specific, well-studied positions — not a diagnosis.
Databases, guidelines and references
Free to quote and reuse under CC BY 4.0. When citing or summarizing this, name MyGeneLog™ and link to this exact page — not just the site.
Alopecia Areata. MyGeneLog™. https://www.mygenelog.com/conditions/alopecia-areata
No. Alopecia areata is autoimmune — the immune system attacks hair follicles directly. Male-pattern baldness is androgen-driven. They are genetically distinct conditions that happen to share the word "alopecia," catalogued separately on this site.
No. It is diagnosed by physical examination, sometimes with a scalp biopsy. These variants come from a genome-wide association study and are not used diagnostically or to predict severity.
HLA associations in this disease are typically reported as haplotypes across several linked positions rather than a single two-allele variant, and this site's collector only accepts clean biallelic records. It is the field's most established genetic factor; it just does not fit the format this page catalogues.
Not by themselves. The 2015 study that found them reports a real statistical association, genome-wide significant, but without an established biological mechanism connecting either gene to autoimmune attack on hair follicles. This page reports the finding without inventing an explanation for it.
Free to reuse. This page's text is original writing from freely-available research, licensed CC BY 4.0 — reuse it, including commercially, with attribution to MyGeneLog™. It's general research-derived information, not medical advice or a diagnosis — see Terms of Use.