Rare variants in mucin-encoding genes in patients with recurrent vulvovaginal candidiasis

Recurrent vulvovaginal candidiasis (RVVC) is a condition characterized by recurrent episodes of vulvovaginal candidiasis, caused primarily by Candida albicans. Host genetic variations may play a role in the susceptibility to this disease. We performed whole-exome sequencing (WES) in patients with RVVC to identify potentially deleterious genetic variants in candidate genes, assess their impact on gene expression. We searched for patients with severe RVVC (>10 episodes per year) and who had additional affected family member(s). WES was performed on gDNA from the index patients. Vaginal scraping samples were obtained from the affected females, and total RNA was obtained to evaluate the expression of candidate genes by qPCR. We identified 12 adult females affected with severe RVVC across 11 families, of whom three had more than one affected female. In silico analyses of WES results revealed potentially deleterious variants in MUC4, MUC5B, and MUC21 genes. A significant decrease in the expression of the MUC5B and MUC21 genes was observed in patients with RVVC compared to healthy women. These results suggest that potentially deleterious variants could affect the expression of the genes encoding different members of the mucin family, indicating that mucins may play a significant role in the pathogenesis of RVVC.