Nod2, Not Yet.

Scientists' motivation for identifying susceptibility genes for Crohn's disease (CD) include an increased understanding of disease etiology and pathogenesis, the development of therapeutic and preventive strategies, the introduction of a molecular classification of the heterogeneous condition that is CD, the possibility of accurately predicting disease course and response to therapy, the use of genetic markers as a diagnostic aid for CD, and the ability to predict the risk of developing CD for genetic counseling. The identification of NOD2(CARD15) as a susceptibility gene for CD was a highly significant advance in our understanding of CD pathogenesis and in complex disease genetics as a whole. Mutations within NOD2 are associated with CD in all studies of white populations, but mutations are not found in Asian populations. In whites, 70% of the attributable risk of developing CD can be accounted for by NOD2 in nearly 40% of patients with CD that carry a NOD2 mutation.1