Lack of linkage of familial Wilms' tumour to chromosomal band 11 p13

Wilms' tumour (WT), a paediatric renal neoplasm, affects approximately 1 in 10,000 children. One or both kidneys can be affected and 5-10% of tumours are bilateral¹. Most tumours occur sporadically; however, around 1% of the cases are familial, with siblings or cousins most often being affected². Familial cases are more frequently bilateral³, and familial and bilateral tumours are diagnosed at an earlier age¹. On the basis of these observations, it was proposed that the development of WT requires two mutations⁴. In most sporadic unilateral WT, both are somatic; in familial and bilateral tumours the first is thought to be germinal. Cytogenetic and molecular studies have demonstrated germinal mutations in WT/aniridia patients and somatic mutations in sporadic WT at chromosomal band 11p13. To investigate whether familial predisposition to WT is due to a germinal 11p13 mutation, we studied a WT family with seven DNA markers that span the 11p13region. We found that familial WT predisposition was not genetically linked to any of the 11p13 markers. This suggests that the gene involved in familial WT predisposition is outside 11p13 and is distinct from the gene involved in tumorigensis and in WT predisposition in WT/aniridia 11p13-deletion patients.