Objectives: Certain genetic variants in the CARD15 gene are accompanied by an enhanced risk to develop Crohn disease with the main activity in the terminal ileum and ensuing stricturing early in life. The objective of this study was to evaluate the relation between CARD15 mutations and overall disease activity and response to therapy in pediatric patients.

Methods: 65 genomic DNA samples from such patients were tested for the presence of three main Crohn associated mutations in CARD15 by direct genomic sequencing. The number of mutations (none, one or two alleles affected) was correlated with body mass index and height, Pediatric Crohn Disease Activity Index, therapy and therapeutical success in terms of body mass index and Pediatric Crohn Disease Activity Index improvement.

Results: The authors found a nonsignificant trend of a lower body mass index and higher Pediatric Crohn Disease Activity Index in patients with CARD15 mutations. Physicians uninformed about their CARD15 status prescribed significantly more budesonide and prednisolone intermittently and more alimentary supplementation to these patients. The average improvement in terms of body mass index and Pediatric Crohn Disease Activity Index after 2 years of therapy was roughly similar in all patient groups.

Conclusions: Pediatric Crohn patients with CARD15 mutations have a higher disease activity and need a more intensive therapy. With some exceptions, their medium-term response to therapy is nevertheless satisfying.