Genetic coding variant in complement factor B (CFB) is associated with increased risk for perianal Crohn’s disease and leads to impaired CFB cleavage and phagocytosis

Perianal Crohn's disease (pCD) occurs in up to 40% of patients with CD and is associated with poor quality of life, limited treatment responses and poorly understood aetiology. We performed a genetic association study comparing CD subjects with and without perianal disease and subsequently performed functional follow-up studies for a pCD associated SNP in