Table 3. IDO1 Variants and Crohn's Disease Phenotype.

Characteristic	CD Group without any IDO1 Variant (726 patients)	CD Group with any IDO1 Variant (8 patients)	P Value
Mean Age at Diagnosis in years (SD)	28.28 (13.00)	30.63 (12.53)	0.614
Age Range at Diagnosis in years	1–77	17–50
Gender
Male (%)	324 (44.63%)	4 (50.00%)	0.737
Female (%)	402 (55.37%)	4 (50.00%)	0.737
Race
White (%)	651 (89.67%)	3 (37.50%)	<0.001
Black (%)	63 (8.68%)	5 (62.50%)	<0.001
Other (%)	12 (1.65%)	0	1.000
Family History of IBD (%)
No	563 (77.5%)	6 (75%)	1.000
First degree	86 (11.8%)	1 (12.5%)
Second degree	70 (9.6%)	1 (12.5%)
Unknown	7 (1.0%)
History of IBD-Related Surgery (%)
One surgery	484 (66.7%)	8 (100.00%)	0.058
Two surgeries	211 (29.1%)	4 (50%)
> 2 surgeries	89 (12.3%)	2 (25%)
Use of Steroid Sparing Medication	453 (62.4%)	8 (100%)	0.0288
Extra Intestinal Manifestations (%)	169 (23.28%)	6 (75.00%)	0.0031 *
Montreal Disease Classification
Location
L1: Terminal ileum or cecum only (%)	313 (43.11%)	2 (25.00%)	0.477
L2: Colon only (%)	152 (20.94%)	1 (12.50%)	1.000
L3: Terminal ileum and colon (%)	256 (35.26%)	5 (62.50%)	0.141
L4: Upper small bowel only (%)	5 (0.69%)	0	1.000
Upper Small Bowel Involvement (%)	88 (12.12%)	1 (12.50%)	1.000
Disease Behavior
B1: Inflammatory (%)	238 (32.78%)	3 (37.50%)	0.722
B2: Stricturing (%)	198 (27.27%)	3 (37.50%)	0.691
B3: Penetrating (%)	290 (39.94%)	2 (25.00%)	0.488
Perianal Involvement (%)	209 (28.79%)	6 (75.00%)	0.0096 *

*These values remained significant in univariate analysis when comparing within black race only. EIMs: 15/63 vs 5/5, P = 0.002; Perianal involvement: 20/63 vs 4/5, P = 0.049 Use of steroid sparing medication did not meet significance when comparing within black race only: 31/63 vs 5/5, P = 0.056.