Familial risk estimated for inflammatory bowel disease

The risk for a patient with inflammatory bowel disease (IBD) having a first-degree relative (FDR) with IBD is increased, according to a study published in the August issue of Alimentary Pharmacology & Therapeutics.

Jonas Halfvarson, M.D., Ph.D., from Örebro University in Sweden, and colleagues estimated familial aggregation of IBD. The analysis included 50,667 individuals diagnosed with IBD between 2003 and 2017 with at least one FDR and 506,720 individuals from the general population with at least one FDR.

Compared with controls, the researchers found that IBD cases more often had a mother (odds ratio, 3.5), father (odds ratio, 3.5), full sibling (odds ratio, 3.6), and child (odds ratio, 2.6) with IBD. The association was stronger with a higher number of affected FDRs. The highest odds ratios were seen for pediatric IBD among pediatric-onset Crohn disease (odds ratio, 10.6) and pediatric-onset ulcerative colitis (odds ratio, 8.4) cases. In full siblings of incident IBD patients, the 10-year cumulative incidence of IBD was 1.7 percent compared with 0.4 percent among full siblings of reference individuals.

"The variations in the strength of familial IBD and future risk of IBD in FDRs support differences in genetic predisposition and call for targeted approaches in potential screening programs," the authors write.

Several authors disclosed financial ties to biotechnology and pharmaceutical companies.