Fecal microbiota and association with IBD were analyzed in patients with chronic granulomatous disease (CGD, 10 patients), X-linked inhibitor of apoptosis (XIAP) deficiency (six patients) and partial tetratricopeptide repeat domain 7A (TTC7A) deficiency (five patients), and compared to non–genetically-determined/polygenic IBD (18 patients) and 23 healthy subjects [134]. The gene discussed is XIAP; the disease is chronic granulomatous disease.