The study examined changes in DNA 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 study included information gleaned from 993 families with IBD, 244 of whom were Ashkenazi Jews. 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. 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.
By analyzing common DNA variations known as single nucleotide polymorphisms, or SNPs, the team found evidence for genes causing familial Crohn’s Disease in the study population specific to Ashkenazi Jewish families with CD on previously identified areas of chromosomes one and three. They also identified a never-before-identified region of chromosome 13 that was shared by both Jewish and non-Jewish families with CD. Evidence for chromosomal regions that may be linked to UC on chromosome two and 19 for Jewish and non-Jewish families was also noted, according to Steven R. Brant, M.D., senior author of the study.
“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, says Brant.” The new process is ten times faster than older methods at searching the number of variations across the genome, he added.
MEDICA.de; Source: Johns Hopkins Medical Institutions