A subset of affected patients (10/18) and CD controls (147 of 172) treated with IFX but without the development of psoriasis were genotyped for polymorphisms in the interleukin-23 receptor (IL-23R) gene, which has been identified as conferring susceptibility to both CD and psoriasis.
We confirmed the findings that the IL-23 receptor gene coding variant allele R381Q appears to decrease susceptibility to CD in an Israeli Jewish population.
The use of techniques such as whole genome association studies to perform broad, unbiased screening for the contributions of common genetic variations to complex disease has rapidly assisted in the identification of several novel susceptibility loci associated with pediatric-onset Crohn's disease such as IL23R and ATG16L1.