A new study has identified genetic markers for Crohn's disease and has also revealed that Ashkenazi Jews have an inherited risk of developing the inflammatory bowel disease.
The researchers examined the DNA changes associated with the two most common forms of inflammatory bowel disease (IBD), Crohn's Disease (CD), which is most frequently marked by inflammation of the final section of the small bowel (ileum) and parts of the colon, and Ulcerative Colitis (UC), an inflammation of the internal lining of the rectum and colon.
The researchers gathered the information from 993 families with IBD, 244 of whom were Ashkenazi Jews.
Nearly 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.
The findings revealed that people of Ashkenazi Jewish descent were twice as likely to develop a form of IBD and are more likely to have familial disease.
The analysis of DNA variants known as single nucleotide polymorphisms, or SNPs found evidence for genes causing familial Crohn's Disease in the study population specific to Ashkenazi Jewish families with CD
They also identified a never-before-identified region of chromosome 13 that was shared by both Jewish and non-Jewish families with CD.
"This increased risk for some Jewish people makes our study and results especially significant since this is the first sample size of Jewish families, 244, that was large enough to identify novel gene regions for familial predisposition in this ethnic group," said Dr Steven R. Brant, senior author, Johns Hopkins gastroenterologist and genetic investigator.
"What makes these results especially significant is not only the large sample size but also the method we used for screening, namely the use of a high-density, single-nucleotide polymorphism genome-wide linkage process," he added.
However, further study is needed to identify which specific genes are the major players.
The study is published in this month's edition of Genes and Immunity.