The initial screening for pathogenic variants in established monogenic IBD genes identified a nonsense mutation in CYBB (p.W380X) in a 31-year-old male patient of European descent with infantile-onset of granulomatous colitis, perianal abscesses and hidradenitis suppurativa (Fig. 1a, f; Table 1). This evidence concerns the gene CYBB and hidradenitis suppurativa.