Table 1. Baseline characteristics of patients.

Patient ID	Sex	Age at IBD diagnosis (years)	Mutation	Intestinal symptoms	Endoscopic and histological findings	Paris Classification	Extra-intestinal manifestations
1	F	12.4	c.3019C>G (p.P1007A) and c.3731T>C (p.L1244P)	Diarrhoea, rectal bleeding, pain on defecation, perianal fissures, anorectal and vaginal fistula, arthritis	Aphthous lesions in the colon + fistulas Histology - inflammatory infiltrates, no granulomas.	A1bL2B1p
2	F	2.9	compound heterozygous for c.2678dupT and c.3107C>T also heterozygous for c.29T>G	Rectal bleeding and diarrhoea	Severe left sided disease, inflammatory stricture of distal rectum, severe perianal skin tagging.	A1aB2B3pL2G1 #	Respiratory infections, growth delay, neurological deterioration with swallowing dysfunction
3	F	13.6	c.2848G>A and c.423_424dupGA.	Diarrhoea with blood, weight loss	Mild colitis endoscopically with granulomas on biopsy	A1bL2B1G0	Progressive motor, speech and bulbar dysfunction with swallowing dysfunction and moderate OSA (uses CPAP). Wilms tumour age 4 (surgery and chemotherapy)
4	M	4.2	p.Ile1061Thr and p.Ser847Pro	Perianal pain, weight loss	Perianal skin tags and fissures, macroscopically normal colon and terminal ileum. Histology – IEL and granulomas	A1aB1pL1G0	Splenomegaly, no neurological symptoms at present

^# : unable to have complete assessment at colonoscopy due to disease severity. 1* represents patient 8 in Schwerd et al., 4 ⁺ patient case report previously published ¹³

IEL: intraepithelial lymphocytes