The Simpson-Golabi-Behmel gene, GPC3, is not involved in sporadic Wilms tumorigenesis

Many genes have been implicated in Wilms tumor; however, only one gene, WT1, has a proven role in the development of this embryonal tumor. Wilms tumor occurs in a number of congenital syndromes including the Simpson-Golabi-Behmel syndrome (SGBS) which has phenotypic overlap with another Wilms tumor-predisposing syndrome Wiedemann-Beckwith syndrome. The putative function and expression pattern of the SGBS gene, glypican 3 (GPC3), makes it an attractive candidate Wilms tumor gene. We, therefore, hypothesized that Wilms tumors from non-SGBS patients may harbor somatic mutations of GPC3. Mutation analysis of 64 Wilms tumors was performed. One case of a tumor-specific deletion of the entire GPC3 gene and several polymorphisms were identified. GPC3 expression was evaluated in 36 Wilms tumors and 29/36 expressed GPC3. Surprisingly, we did not find evidence of functional mutations of GPC3 in sporadic Wilms tumor suggesting that GPC3 is not often directly involved in Wilms tumorigenesis. (C) 2003 Wiley-Liss, Inc.