Monogenic inflammatory bowel disease: An unfolding enigma

Table 2 Clinical clues towards specific etiologies of monogenic inflammatory bowel disease

Clinical clues	Underlying condition/affected genes
Epidermolysis bullosa, nail dystrophy	Epithelial barrier defect (IKBKG, a disintegrin and metalloproteinase 17, COL7A1)
Woolly hair, trichorrhexis nodosa	Tricho-entero-hepatic syndrome
Severe perianal disease (rectovaginal fistula), folliculitis, and/or arthritis	IL-10 signaling pathway defects
Abscess without pus	Leukocyte adhesion defect
Eczema	Wisckot-Aldrich syndrome, hyper immunoglobulin E syndrome, IPEX syndrome, IKBKG defect
Hepatosplenomegaly	Chronic granulomatous disease
Autoimmune anemia, type 1 diabetes mellitus, autoimmune thrombocytopenia, autoimmune thyroiditis, interstitial pneumonia	IPEX, IPEX-like syndromes
No bacillus calmette-guerin scar	T cell defect
Oral ulcer, leukoplakia	Dyskeratosis congenita 1, regulator of telomere elongation 1
Dysmorphic features	IKBKG, mucosa-associated lymphoid tissue lymphoma translocation protein 1, glucose-6-phosphatase-catalytic subunit 3, SKIV2 L
Hemophagocytic lymphohistiocytosis, macrophage activation syndrome	X-linked inhibitors of apoptosis, mevalonate kinase, syntaxin-binding protein-2
Periostosis	Solute carrier organic anion transporter family member 2A1
Albinism	Hermansky-Pudlak syndrome 1/4/6
Malignancy (lymphoma, gastric adenocarcinoma)	IL-10/IL-10RA/B, lipopolysaccharide-responsive and beige-like anchor protein, cytotoxic T lymphocyte antigen-4
Absent tonsils	Agammaglobulinemia

IKBKG: Inhibitor of nuclear factor-kappa B kinase regulatory subunit gamma; IL: Interleukin; IPEX: Immune dysregulation, polyendocrinopathy, enteropathy, X-linked.