Familial aggregation of inflammatory bowel disease in patients with ulcerative colitis

BACKGROUND/AIMS Familial occurrence of inflammatory bowel disease (IBD) is well documented. Reports from Western countries have shown a higher familial occurrence of ulcerative colitis (UC) in first- and second-degree relatives than that in the Asian UC population. No data are currently available from the Indian subcontinent in this regard. We present our data on the familial aggregation of UC. METHODS Records of patients with UC followed at the Inflammatory Bowel Disease Clinic at the All India Institute of Medical Sciences, New Delhi from August 2004 to January 2016 were reviewed. Details regarding the prevalence of family history and characteristics of these patients were recorded. Affected family members were contacted and disease characteristics were noted for assessment of familial aggregation. RESULTS Of the 2,058 UC patients included in the analysis, a positive family history of IBD was confirmed in 31 patients (1.5%), 24 (77.4%) of whom had only first-degree relatives affected. All the affected relatives had UC and none had Crohn's disease. Among first-degree relatives, siblings were found to have the highest prevalence of IBD (53.3%), followed by parents (26.7%). CONCLUSIONS The probability of occurrence of IBD in family members of affected North Indian UC patients is lower than that reported in Western populations.