ORLANDO, FLA. — Crohn's disease patients with two allelic variants of the NOD2/CARD15 gene have an increased risk of upper GI disease involvement, Houssam E. Mardini, M.D., reported at the annual meeting of the American College of Gastroenterology.
Genetic testing of patients in an inflammatory bowel disease database revealed that six of nine patients with Crohn's disease in the upper GI tract had two allelic variants of the NOD2/CARD15 gene.
In comparison, a significantly lower percentage of patients without upper GI disease had two allelic variants of the gene (4% of 169). “Our data suggest that patients with two NOD2/CARD15 allelic variants should be carefully evaluated for upper GI involvement,” Dr. Mardini and his associates said in a poster presentation.
NOD2/CARD15 is so far the only gene that is highly associated with Crohn's disease. Four of the patients with upper GI disease had homozygous allelic variants, whereas none of the patients without upper GI disease were homozygous for an allelic variant. Wild type alleles of NOD2/CARD15 occurred in 68% of the patients without upper GI disease; another 28% of those without upper GI disease had one allelic variant.
Compared with patients who did not have upper GI disease, significantly more of the patients with upper GI involvement had a family history of inflammatory bowel disease (19% vs. 44%), were male (41% vs. 78%), and were younger at diagnosis (25 years vs. 17 years). Osteopenia or osteoporosis developed significantly more often in patients with upper GI disease than in those without (33% vs. 9%).