Summary of patient phenotypes and characteristics (specific selection criteria are in bold)
| Sample ID | Age at diagnosis (years) | Sex | Disease | Phenotype description and selection criteria | Ethnicity | Family history |
| Proband 1 | 11 | Male | CD | Severe disease requiring surgery/ Stricturing ileo-colonic disease requiring right hemicolectomy within 6 months of diagnosis. | White British | – |
| Proband 2 | 7 | Female | CD | Early age of onset/non-stricturing, non-penetrating mild to moderate pancolitis, disease resistant to treatment. | White British | – |
| Proband 3 | 6 | Male | CD | Early age of onset/non-stricturing, non-penetrating granulomatous colitis and duodenitis. Mother diagnosed CD aged 21 years. | White British | + |
| Proband 4 | 6 | Female | CD | Early age of onset/non-penetrating pancolitis with possible ileo-caecal stricture. | White British | – |
| Proband 5 | 13 | Male | CD | Non-stricturing, non-penetrating, colitis. Family history including maternal CD and maternal grandparental UC. | White British | + |
| Proband 6 | 9 | Male | UC | Severe left sided colitis, also with oral pemphigus. | White British | – |
| Proband 7 | 2 | Male | UC | Early age of onset/mild to moderate pancolitis. | White British | – |
| Proband 8 | 3.5 | Male | IBDU | Early age of onset/left sided colitis. | Iraqi | – |
CD, Crohn's disease; IBDU, inflammatory bowel disease unclassified; UC, ulcerative colitis.