von Hippel-Lindau disease (VHL) is an autosomal dominant inherited disease, frequently accompanied by occurrences of renal cell carcinoma (RCC). Both the VHL gene and tumor suppressor genes for RCC have been mapped to the short arm of chromosome 3, although the genes have not yet been identified. An RCC cell line, KC12, was established from a VHL patient. Molecular genetic analyses in conjunction with cytogenetic studies revealed that the short arm of chromosome 3 distal to the D3S4 locus at 3p11 was lost in the RCC cell line as a result of an unbalanced translocation between chromosomes 3p and 5q. Structural and numerical aberrations, including those on chromosome 3p, were not detected in T-lymphocytes from the patient, suggesting that the inherited mutation of the VHL gene at 3p25-26 in this patient was too subtle to be detected by either Southern blot or karyotype analysis. Since no permanent RCC cell line has been established from a VHL patient, this cell line will be a useful source for analyzing the VHL gene at 3p25-26 and tumor suppressor gene(s) at 3p13-21.