Inflammatory bowel disease–like conditions: monogenic gastrointestinal disorders

Abstract A small subset of patients has inflammatory bowel disease (IBD)-like diseases due to monogenic diseases. They have early onset of disease after birth and have severe clinical presentations, including refractory diarrhea and perianal diseases. Some of them might have underlying primary immunodeficiencies. Lower gastrointestinal endoscopy often demonstrates predominant colonic involvement, and in patients with IL10RA mutations, severe and deep ulcerations are common. However, endoscopic and histopathological findings in monogenic IBD-like disease are usually not specific. Immunological investigations and genetic sequencing are therefore required. Accurate diagnosis enables physicians to carry out precise treatment promptly, such as the use of hematopoietic stem-cell transplantation in those with certain genetic defects. Patients with monogenic IBD-like diseases typically do not respond well to conventional therapy used in adult IBD counterparts.