A gene identified through positional cloning has been determined to be the von Hippel-Lindau (VHL) disease tumor suppressor gene. Analysis of restriction fragments in 221 VHL families revealed rearrangements in 28 cases, with 18 involving deletions in the candidate gene, including three large non-overlapping deletions. Intragenic mutations were found in cell lines from VHL patients and sporadic renal cell carcinomas. The VHL gene is evolutionarily conserved and produces two widely expressed transcripts of approximately 6 and 6.5 kilobases. The partial sequence of the inferred gene product shows no homology to other proteins, except for an acidic repeat domain found in the procyclic surface membrane glycoprotein of Trypanosoma brucei. VHL disease is a familial cancer syndrome with dominant inheritance, predisposing affected individuals to various tumors, including hemangioblastomas of the central nervous system and retina, renal cell carcinoma (RCC), and pheochromocytoma. The incidence is one in 36,000, with near-complete penetrance by 65 years of age, and a median actuarial life expectancy of 49 years, with RCC being the most common cause of death. Genetically, the disease gene functions as a typical tumor suppressor, as defined in Knudson's theory of human carcinogenesis. Using positional cloning strategies, the VHL gene region on human chromosome 3p25-p26 was delineated, with nearly complete genomic coverage in overlapping yeast artificial chromosomes (YACs) and cosmid-phage contigs. A physical map of the region was established using pulsed-field gel electrophoresis, and gross rearrangements were identified. These efforts led to the discovery of nested constitutional deletions in three unrelated VHL patients, providing rapid access to the VHL gene. The study highlights the importance of positional cloning in identifying tumor suppressor genes and understanding the genetic basis of VHL disease.A gene identified through positional cloning has been determined to be the von Hippel-Lindau (VHL) disease tumor suppressor gene. Analysis of restriction fragments in 221 VHL families revealed rearrangements in 28 cases, with 18 involving deletions in the candidate gene, including three large non-overlapping deletions. Intragenic mutations were found in cell lines from VHL patients and sporadic renal cell carcinomas. The VHL gene is evolutionarily conserved and produces two widely expressed transcripts of approximately 6 and 6.5 kilobases. The partial sequence of the inferred gene product shows no homology to other proteins, except for an acidic repeat domain found in the procyclic surface membrane glycoprotein of Trypanosoma brucei. VHL disease is a familial cancer syndrome with dominant inheritance, predisposing affected individuals to various tumors, including hemangioblastomas of the central nervous system and retina, renal cell carcinoma (RCC), and pheochromocytoma. The incidence is one in 36,000, with near-complete penetrance by 65 years of age, and a median actuarial life expectancy of 49 years, with RCC being the most common cause of death. Genetically, the disease gene functions as a typical tumor suppressor, as defined in Knudson's theory of human carcinogenesis. Using positional cloning strategies, the VHL gene region on human chromosome 3p25-p26 was delineated, with nearly complete genomic coverage in overlapping yeast artificial chromosomes (YACs) and cosmid-phage contigs. A physical map of the region was established using pulsed-field gel electrophoresis, and gross rearrangements were identified. These efforts led to the discovery of nested constitutional deletions in three unrelated VHL patients, providing rapid access to the VHL gene. The study highlights the importance of positional cloning in identifying tumor suppressor genes and understanding the genetic basis of VHL disease.