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Updated: May 15, 2026

Candidate Gene Testing in Clinical Cohort Studies with Multiplexed Genotyping and Mass Spectrometry
Published on: June 21, 2018
Genotype/phenotype analyses for 53 Crohn's disease associated genetic polymorphisms
Camille Jung1, Jean-Frédéric Colombel, Marc Lemann
1Université Paris Diderot, UMR843, Paris, France.
Genetic variations in Crohn's disease (CD) susceptibility genes show limited clinical utility. While some polymorphisms correlate with disease presentation, these findings often lack statistical significance for routine genetic testing in CD patients.
Area of Science:
- Genetics
- Gastroenterology
- Immunology
Background:
- Over 70 genes/loci are linked to Crohn's disease (CD) susceptibility.
- The clinical impact of these genetic associations remains unclear.
- This study investigates genotype-phenotype correlations in CD.
Purpose of the Study:
- To analyze the relationship between specific genotypes and clinical phenotypes in Crohn's disease.
- To evaluate the practical application of 53 known CD-associated polymorphisms.
Main Methods:
- A cohort of 798 CD patients was genotyped for 53 CD-associated variants.
- Detailed phenotypic data including presentation, treatment response, and complications were collected.
- A replication cohort of 722 CD patients was used to validate findings.
Main Results:
- NOD2 variants associated with earlier diagnosis and ileal involvement.
- IL23R and 6q21 variants linked to colonic lesions; IRGM and DEFB1 variants showed inverse associations.
- ATG16L1 and IRGM variants correlated with non-inflammatory disease behavior, but lost significance after corrections.
- IRGM's protective effect on colonic lesions was the sole replicated finding.
Conclusions:
- Current genotype-phenotype correlations for these CD-associated polymorphisms lack robust clinical applicability.
- Routine genetic testing for these specific variants in clinical practice is not recommended based on this study.
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