Wilms tumor associated with hirschsprung disease.

Hirschsprung disease (HD) has been associated with multiple renal malformations. We describe a child with HD who also had Wilms tumor (WT). Because the RET protooncogene, the major susceptibility gene for HD, also plays a role in normal kidney development and in the multiple endocrine neoplasia type 2 cancer syndrome, we analyzed our patient's constitutional DNA for mutations in RET commonly found in multiple endocrine neoplasia type 2A. Although this limited evaluation failed to show abnormalities, we speculate that comprehensive analysis of the RET gene may identify mutations to account for the development of WT in this and other children with WT.