Objective:

To identify genetic interactions influencing the risk of frontal fibrosing alopecia (FFA) through a genome-wide meta-analysis.

Approach:

• Study Design: Combined four genome-wide association studies (GWAS) involving 1,585 female patients with FFA and 5,083 controls, analyzing over 8 million genetic variants.

Key Findings:

• Identification of a novel susceptibility locus at 5q15 linked to the ERAP1 gene.
• Independent associations found with four major histocompatibility complex (MHC) class I alleles: HLA-A*11:01, HLA-A*33:01, HLA-B*07:02, HLA-B*35:01.
• ERAP1 variants increased FFA risk only in individuals carrying at least one of the MHC alleles, indicating a supra-additive genetic effect.
• FFA characterized as an oligogenic, immune-mediated disorder distinct from lichen planus.

Interpretation:

Limitations:

• The study focused on European female participants, necessitating further research in more diverse populations.
• Additional functional studies are required to clarify the role of ERAP1-MHC interactions in FFA pathogenesis.

Conclusion:

Sources:

• JAMA Dermatology