Alterations of the CARD15/NOD2 gene and the impact on management and treatment of Crohn's disease patients

The recent identification of the CARD15/NOD2 gene as a
susceptibility locus for Crohn's disease represents an important
step towards the delineation of the immuno-pathogenesis of
inflammatory bowel disease. CARD15 functions as an intracellular
receptor for bacterial components and thus represents an important
link between inflammatory bowel disease and innate immunity. Three
major CARD15/NOD2 gene mutations have been associated with Crohn's
disease in Caucasians in several independent studies. Together,
they explain about 20% of the genetic susceptibility for Crohn's
disease. Genotype-phenotype analyses demonstrated an association of
these mutations with ileum-specific disease, an increased incidence
of the fibrostenotic phenotype and an earlier age of disease onset.
Beside these associations, no other relationship between the
CARD15/NOD2 genotype and disease behavior or response to treatment
has been detailed so far. Thus, the clinical impact of knowing the
patient's genotype is limited at this time. Screening for CARD15
mutations in order to identify high-risk individuals or to
introduce an individualized disease management is therefore
currently not recommended. Copyright (C) 2003 S. Karger AG, Basel.