Identification of somatic mutations in the von Hippel-Lindau (VHL) gene in a patient with renal cell carcinoma.

One of the known causal molecular events in renal cell carcinoma is somatic mutation in the von Hippel-Lindau (VHL) gene. Our study describes a 51-year-old Taiwanese man who had bilateral renal cell carcinoma. The patient underwent radical nephrectomy without postoperative chemotherapy or radiotherapy, and is still alive after renal transplantation without tumor recurrence after > 5 years. To clarify his predisposition for bilateral tumors, we performed molecular genetic analysis of the VHL gene in this study. Polymerase chain reaction-single-strand conformation polymorphism and direct sequencing were performed on DNA of blood samples and paraffin-embedded tumor specimens from this patient. DNA from peripheral blood lymphocytes tested negative for germline mutations. However, there were two heterozygous alleles in the promoter and 3 untranslated regions of this gene. Nonetheless, the DNA from his tumors showed loss of heterozygosity (LOH) in these two loci. In addition to the LOH, we identified some different somatic mutations in his tumor tissues: C287T and G460A in the right-sided tumor, and G244A and G390A in the left-sided tumor. The possible roles of these genetic polymorphisms and point mutations in his renal tumorigenesis are discussed. This report provides new insights into renal cell carcinoma that result from VHL gene alterations in Taiwan.