[A case of familial Crohn's disease observed in a parent and his offspring].

Crohn's disease (CD), one of the major forms of idiopathic inflammatory bowel disease (IBD), is thought to be related to genetic susceptibility coupled with environmental factors. A positive family history is the strongest risk factor for the development of CD. The 10-fold increase in the familial risk of CD strongly suggests that these disorders have a genetic background. The prevalence of IBD in Asian populations is lower than in Western populations, which may be due to genetic influences, environmental factors, or a combination of both. In a Korean study, only 0.25% of parents had IBD in CD probands and all of them had ulcerative colitis. The term of familial CD was used only for those with one or more first-degree relatives with confirmed CD. There are few case reports about familial Crohn's disease in Korea. We report a case of familial CD that the father, the first degree relative was diagnosed as small bowel CD after confirming his son as having CD.