Differences in risk of Crohn's disease in offspring of mothers and fathers with inflammatory bowel disease.

Objective: To determine whether there are any unusual patterns of transmission of susceptibility to inflammatory bowel disease (IBD) within multiplex families. Methods: Individuals with IBD were recruited for genome-wide screening of susceptibility genes. The extent of familial aggregation and blood relationships in multiplex families were determined by questionnaires given to participants followed up by confirmation of disease diagnosis by participants' physicians. Results: Of 135 families identified in which both a parent and a child had IBD, 93 involved transmission of susceptibility to disease from mother to child versus 42 examples of transmission from father to child (p = 0.00001, exact two-tailed binomial test). This distortion in transmission on the basis of the sex of the parent was observed only among non-Jewish pairs with Crohn's disease (CD), in which, of 33 parent-child pairs with CD, disease susceptibility was transmitted from the mother 28 times (p = 0.00007). Conclusion: Susceptibility to CD in a subset of patients may involve a gene that is imprinted.