Wilms' tumor, malformative syndrome, mental retardation and de novo constitutional translocation, t(7;13)(q36;q13)

Syndromes and constitutional chromosomal abnormalities associated with Wilms tumour

Wilms tumour has been reported in association with over 50 different clinical conditions and several abnormal constitutional karyotypes. Conclusive evidence of an increased risk of Wilms tumour exists for only a minority of these conditions, including WT1 associated syndromes, familial Wilms tumour, and certain overgrowth conditions such as Beckwith-Wiedemann syndrome. In many reported conditions the rare co-occurrence of Wilms tumour is probably due to chance. However, for several conditions the available evidence cannot either confirm or exclude an increased risk, usually because of the rarity of the syndrome. In addition, emerging evidence suggests that an increased risk of Wilms tumour occurs only in a subset of individuals for some syndromes. The complex clinical and molecular heterogeneity of disorders associated with Wilms tumour, together with the apparent absence of functional links between most of the known predisposition genes, suggests that abrogation of a variety of pathways can promote Wilms tumorigenesis.

Genetics of Beckwith-Wiedemann syndrome-associated tumors: common genetic pathways

A specific subset of solid childhood tumors-Wilms' tumor, adrenocortical carcinoma, rhabdomyosarcoma, and hepatoblastoma-is characterized by its association with Beckwith-Wiedemann syndrome. Genetic abnormalities found in these tumors affect the same chromosome region (11p15), which has been implicated in the etiology of Beckwith-Wiedemann syndrome. This suggests that the development of these tumors occurs along a common genetic pathway involving chromosome 11. To search for additional common genetic pathways, this article reviews the genetic data published for these tumors. It was found that, up until now, the only genetic abnormalities detected in all four tumors affect chromosome band 11p15 and the TP53 gene. In addition, there are several aberrations that occur in two or three of the neoplasms. It is concluded that, of the four tumors, the genetic relationship is most evident between Wilms' tumor and rhabdomyosarcoma.

Occurrence of cancer in a cohort of 183 persons with constitutional chromosome 7 abnormalities

Cytogenetic abnormalities in human malignancies frequently involve chromosome 7. The existence of several tumor suppressor genes on the long arm of chromosome 7 has been suggested in both epithelial and hematologic malignancies. From the Danish Cytogenetic Register, we identified 183 persons with constitutional abnormalities involving chromosome 7, including 16 patients with Williams syndrome. By linkage to the Danish Cancer Registry, we found five persons with cancer, including one thyroid carcinoma, three carcinomas of the digestive tract, and one malignant melanoma. There were no cases of leukemia. The overall risk of developing cancer was not increased.

Balanced reciprocal translocation (X;20) limited to Wilms' tumor in a Wiedemann-Beckwith syndrome

A girl aged 4 years 3 months with sporadic unilateral Wilms' tumor associated with Wiedemann-Beckwith syndrome, but without aniridia, was found to have a t(X;20) in the tumor cells. Karyotypes of peripheral blood of the patient and her parents were normal. This translocation was confined to the tumor and not been previously reported either in nephroblastoma or any other neoplastic processes. Although there is no microscopic deletion on chromosome 11 and catalase activity was not decreased, we cannot rule out the possibility of a point mutation or a submicroscopic deletion.