Background: The objectives of this multicenter national study were to compare the clinical phenotype of early-onset inflammatory bowel disease (IBD) (EO-IBD) with IBD in older children and to examine whether there is any variability in consanguinity rate and familial aggregation in EO-IBD compared with later onset IBD.
Methods: A retrospective analysis was performed on children aged 0 to 14 years with IBD in 17 centers located in geographically distinct regions in Saudi Arabia, from 2003 to 2012. Data of patients with EO-IBD (0 to <6 yrs) were compared with those with later onset IBD (6-14 yrs). Moreover, we evaluated differences in clinical pattern of infantile or toddler onset IBD subgroup (0-3 yr) as compared with those presenting in older children.
Results: Of 352 IBD patients identified during the 10-year study period, 76 children (21.6%) younger than 6 years were diagnosed with IBD. Among the Crohn's disease (CD) group, infantile or toddler onset CD subgroup showed a more frequent isolated colonic involvement (L2) than later-onset group (57% versus 20%; P = 0.002). Positive family history was significantly more common in the infantile or toddler onset ulcerative colitis subgroup (29.4% versus 4.2% in later onset ulcerative colitis; P < 0.0001). The consanguinity rate was significantly higher in the infantile or toddler onset CD subgroup as compared with later onset CD group (57.1% versus 25.3%; P = 0.04).
Conclusions: In conclusion, EO-IBD exhibits a unique clinical phenotype with a strikingly higher familial aggregation in early-onset ulcerative colitis. Our data suggest a significant genetic impact on the onset of CD in the very young children.