IRF2BP2 and colitis: This event could explain why truncating mutations in exon 1 of IRF2BP2 express mRNA, and it would also be a relevant aspect to further investigations about differences in the phenotype expression associated with genetic defects in IRF2BP2. These results also support the pathogenicity of truncating mutations in IRF2BP2, which are highly penetrant for CVID and show variable expression and severity of gastrointestinal manifestations, especially colitis, with autosomal dominant inheritance.