Crohn disease (CD) (MIM 266600) and Ulcerative Colitis comprise inflammatory bowel disease (IBD), a common, progressive debilitating disease of the bowel which affects about 1 in 500 individuals in the western population. Both conditions seem to involve altered expression of cytokines within the intestinal mucosa and the responses appear to be both distinct and overlapping.

Crohn disease is an inflammatory process that can affect any part of the gastrointestinal tract resulting in pain, blockage, fistulas and scarring. Within 10 years of onset 60% of patients with Crohn disease will need surgical treatment. Risk for colon cancer is also increased. The pathogenesis of Crohn disease appears to involve both environmental and genetic factors. Since the condition is chronic and progressive, early intervention may be valuable in managing the condition. Changes of diet, life style and prophylactic medicines are all effective components in improving the course of the disease. However, often by the time of diagnosis, significant permanent damage has already occurred.

The identification of predictive genetic risk factors in individuals with a family history can be an important component of detection and therapy. Within the NOD2/CARD15 gene (chromosome16q12), 4 autosomal dominant susceptibility loci (R702W, G908R, 3020insC(1007fs) and IVS8+158) have been identified that predispose an individual to Crohn disease (but not ulcerative colitis). In the western population the R702W, G908R and 3020insC markers represent about 80% of the detected mutations with the remainder distributed as a variety of rare mutations. In the Ashkenazi Jewish population the IVS8+158 represents about 50% of the mutational incidence. Approximately 60% of the Crohn disease population has one or more of these predisposing loci; 17% are homozygote for one of these markers.

A second rare granulomatous disorder, Blau syndrome (MIM186580), is also associated with  NOD2/CARD15 gene mutations. Blau syndrome is an autosomal dominant disorder characterized by early-onset granulomatous arthritis, uveitis and skin rash with camptodactyly. Sequencing of the entire gene is necessary to detect the causative mutations.

• Family history of inflammatory bowel disease (IBD).
• To differentiate between Crohn disease and Ulcerative Colitis.
• Cramping and pain in the gut, especially in response to certain foods or stress.
• Diagnosis of IBD by gastrointestinal exams.
• Unexplained blood in the stool.

• DNA sequencing of selected exons containing the susceptibility loci.
• Sequencing of the entire gene is also available to detect rare mutations.

• Blood EDTA (purple top) tubes:  

            Newborn: minimum 1-2 mL          

            Child/Adult: prefer 2 tubes of 3-5 mL

• Prenatal testing: Please contact the laboratory for instructions.

TURNAROUND TIME:    

• Susceptibility Loci: 3 weeks

• Complete Sequencing: 6 weeks

CPT CODES: