Genetic Origin of Crohn’s Disease Investigated

Crohn’s disease (CD) and ulcerative colitis (UC) are the two most common forms of inflammatory bowel disease (IBD), and a recent Johns Hopkins Medical study has revealed that some people of Jewish descent have DNA that puts them at greater risk for IBD.

CD is characterized by “inflammation of the final section of the small bowel (ileum) and parts of the colon.” UC consists of “an inflammation of the internal lining of the rectum and colon.”

IBD is considered to be largely hereditary, meaning a family history of some form of IBD puts one at increased risk. “Up to 30 percent of people with IBD in the United States are estimated to have a family history of the condition, and about 25 percent of these families have both CD and UC in the family,” says the study, adding that “people of Ashkenazi Jewish descent are at least twice as likely to develop a form of IBD and are more likely to have familial disease.”

The study gathered information from 993 families suffering from some form of IBD, with 244 of the families being Ashkenazi Jews. By analyzing DNA variations known as single nucleotide polymorphisms (SNPs), it was found that “genes causing familial Crohn’s Disease [are present] in the study population specific to Ashkenazi Jewish families.”

Past studies had recognized that Ashkenazi Jews were approximately twice as likely to develop CD, but little explanation was given as to why. This study seems to have found the specific chromosomes present in Ashkenazi Jews that leads to this increased risk for developing CD, and further research should provide details as to the actual genes that lead to the development of the disease. This understanding of the genetic origin of IBD could go a long way in better treating and preventing the disease, both in high risk Ashkenazi Jews, and the general population.

Source: Defeat Diabetes Foundation: Vohr, Eric. Johns Hopkins Medicine News Release. March 2008.