Von Hippel-Lindau Disease Gene Research Articles

Metastatic phaeochromocytoma in a 23‐year‐old woman with an unclassified variant in the von Hippel Lindau disease gene: how can the pathogenicity of this variant be determined?

A 23-year-old woman with metastatic phaeochromocytoma was found to have a previously unclassified variant in the von Hippel Lindau disease gene (c.361G>C). We use this case to highlight the issue of unclassified single nucleotide variants and the approaches to help predict whether they are disease causing or neutral. With increasing use of genetic testing, and widespread clinical use of next-generation sequencing around the corner, this issue is likely to become more prominent.

Imaging appearances of von Hippel-Lindau disease

Objective To assess imaging appearances of von Hippel-Lindau disease (VHLD). Methods The clinical and imaging data of ten patients who met VHLD gene diagnostic criteria were retrospectively analyzed.Seven underwent CT abdominal scan,three underwent MRI abdominal scan.All patients underwent MRI cranial scan.Eight patients were treated by surgery,and three of them underwent endoscopic ultrasound guided aspiration biopsy of pancreatic tumors. Results All patients had multiple cysts of the pancreas,eight patients suffered multiple cysts of kidneys.Three patients suffered multiple islet cell tumors of pancreas: one was accompanied with pancreatic serous cystadenoma,another was accompanied with left adrenal pheochromocytoma.Three patients had bilateral renal cell carcinoma (one of them had the right kidney cut off),one patient had right renal cell carcinoma.Two patients suffered cerebellar hemangioblastomas,and one of them was accompanied with mutiple spinal hemangioblastomas and the left retinal hemangioblastoma.Two patients with multiple cysts of pancreas and kidneys had not been found any tumor. Conclusion Multiple cysts of pancreas and kidney are highly suggestive of VHLD.At the same time,endocrine tumors of pancreas,serous cystadenoma of pancreas,adrenal pheochromocytoma,renal carcinomas,multiple hemangioblastomas of central nervous system and retinal hemangioblastoma can also occur in VHLD. Key words: Pancreatic neoplasm; Hemangioblastoma; Renal neoplasms

Somatic mutations of the von Hippel-Lindau disease gene in renal carcinomas occurring in patients with long-term dialysis

Renal cell carcinoma (RCC) frequently occurs in patients with long-term dialysis. Long-term dialysis causes distinctive pathological changes in the kidney, which is known as acquired cystic disease of the kidney (ACDK). It is of great interest to know whether RCCs occurring in the dialytic kidneys harbour the same or similar mutations of the von Hippel-Lindau (VHL) gene as conventional dialysis-unrelated clear cell RCCs so often do. Renal cancer tissues (eight clear cell, two papillary, one Bellini duct and three of the so-called dialysis-specific renal carcinomas) from 13 patients undergoing long-term dialysis were examined for somatic mutations of the VHL disease gene. By means of laser capture microdissection, cancerous and surrounding non-cancerous renal tissues from dialytic patients were subjected to PCR-based direct sequencing of the VHL gene. Direct forward and reverse sequencing showed that three tumours possessed VHL gene mutations (713delG, 500-504del5-bp and 709A>G). These three mutations were identified in clear cell carcinomas occurring in association with end-stage renal disease undergoing dialysis for 194, 147 and 125 months. None of the non-tumour tissues or other carcinoma tissues analysed, including dialysis-specific carcinoma, possessed VHL gene mutations. These results indicate that VHL tumour-suppressor gene mutation is involved in clear cell carcinoma in association with long-term dialysis. Mutation of the VHL gene was not found in any of the dialysis-specific RCCs studied herein.

Retinal Angiomatosis in von Hippel–Lindau Disease: A Longitudinal Ophthalmologic Study

To characterize the clinical course of retinal angiomatosis (RA) in von Hippel-Lindau (VHL) disease. Retrospective observational case series from a tertiary referral center. Fifty-seven consecutive VHL disease patients with RA with a mean follow-up of 7.3 years. A retrospective chart review was performed to characterize the clinical course and functional outcome of RA to substantiate ophthalmic screening recommendations for VHL disease patients. Age and visual acuity (VA) at diagnosis, angioma number, size, fundus position and growth behavior, functional outcome, and risk factors for adverse visual outcome (VA < or =20/1000) were evaluated. The onset of RA was observed to occur between the ages of 5.5 and 62.5 years. Ocular disease was unilateral in 58% of patients at diagnosis; prevalence of bilateral RA as calculated by Kaplan-Meier analysis was 100% at age 56.4 years. Twenty-seven eyes showed an adverse visual outcome, occurring at a mean age of 23.2 years. Risk factors included large angiomas at presentation, first manifestation at a younger age, and symptomatic RA. In most eyes, development of new angiomas was slow and only small angiomas were detected on annual follow-up. Eyes harboring multiple angiomas or RA complicated by retinal detachment were at risk of developing large angiomas after short follow-up intervals. Formation of new angiomas was largely independent of patient age. Retinal angiomatosis in VHL disease bears a high risk of severe vision loss at a young age. In uncomplicated RA, annual ocular screening for presymptomatic angiomas is sufficient. Because RA can occur at any age, lifelong ocular screening is recommended in VHL disease gene carriers starting at preschool age.

Intraoperative ultrasound aids in dissection during laparoscopic partial adrenalectomy.

Adrenal cortical sparing surgery is a relatively new approach to adrenal tumors. Laparoscopic partial nephrectomy is a technically feasible but challenging operation. We describe the use of intraoperative ultrasound to facilitate laparoscopic partial nephrectomy in a population with a hereditary predisposition to multifocal pheochromocytoma. All patients underwent a history, physical examination, serum and urine catecholamine determinations, abdominal computerized tomography-magnetic resonance imaging and metaiodobenzylguanidine scan. The adrenal gland was exposed using a standard 3 or 4 port approach. Intraoperative ultrasound was performed using a 7.5 MHz. 10 mm. transducer placed through a 12 mm. port. After imaging the whole gland and adjacent structures partial adrenalectomy was performed based on intraoperative ultrasound images using a harmonic scalpel or alternatively using a cut and sew technique that provided a 5 mm. margin. Tumors were removed intact and sent for pathological examination. Since 1998, 11 patients have undergone laparoscopic partial adrenalectomy. Intraoperative ultrasound was performed in 7 patients with suspected multiple adrenal masses, including 4 and 3 who underwent unilateral and bilateral laparoscopic partial nephrectomy, respectively. Six of the 7 patients had germline defects in the von Hippel-Lindau disease gene and 1 had no identifiable alteration in the von Hippel-Lindau disease or RET gene. A solitary tumor was identified in 3 cases and multiple lesions were noted in 4. In 1 case intraoperative ultrasound localized a tumor not identified on preoperative imaging that was not readily visible via laparoscopy. Intraoperative ultrasound guided surgical dissection in all cases and identified an extra-adrenal mass in 1 patient with bilateral adrenal masses. There were no complications due to intraoperative ultrasound and no conversions to open surgery. Mean operative time was 335 minutes and mean estimated blood loss was 179 ml. Histological study demonstrated pheochromocytoma in 14 lesions and the extra-adrenal mass proved to be a splenic rest. At short-term followup no recurrences have been noted. All patients retained sufficient adrenal cortical function to avoid steroid replacement therapy. Laparoscopic ultrasound differentiates normal adrenal parenchyma from adrenal tumors and facilitates laparoscopic partial adrenalectomy.

Intraoperative Ultrasound Aids in Dissection During Laparoscopic Partial Adrenalectomy

Adrenal cortical sparing surgery is a relatively new approach to adrenal tumors. Laparoscopic partial nephrectomy is a technically feasible but challenging operation. We describe the use of intraoperative ultrasound to facilitate laparoscopic partial nephrectomy in a population with a hereditary predisposition to multifocal pheochromocytoma. All patients underwent a history, physical examination, serum and urine catecholamine determinations, abdominal computerized tomography-magnetic resonance imaging and metaiodobenzylguanidine scan. The adrenal gland was exposed using a standard 3 or 4 port approach. Intraoperative ultrasound was performed using a 7.5 MHz. 10 mm. transducer placed through a 12 mm. port. After imaging the whole gland and adjacent structures partial adrenalectomy was performed based on intraoperative ultrasound images using a harmonic scalpel or alternatively using a cut and sew technique that provided a 5 mm. margin. Tumors were removed intact and sent for pathological examination. Since 1998, 11 patients have undergone laparoscopic partial adrenalectomy. Intraoperative ultrasound was performed in 7 patients with suspected multiple adrenal masses, including 4 and 3 who underwent unilateral and bilateral laparoscopic partial nephrectomy, respectively. Six of the 7 patients had germline defects in the von Hippel-Lindau disease gene and 1 had no identifiable alteration in the von Hippel-Lindau disease or RET gene. A solitary tumor was identified in 3 cases and multiple lesions were noted in 4. In 1 case intraoperative ultrasound localized a tumor not identified on preoperative imaging that was not readily visible via laparoscopy. Intraoperative ultrasound guided surgical dissection in all cases and identified an extra-adrenal mass in 1 patient with bilateral adrenal masses. There were no complications due to intraoperative ultrasound and no conversions to open surgery. Mean operative time was 335 minutes and mean estimated blood loss was 179 ml. Histological study demonstrated pheochromocytoma in 14 lesions and the extra-adrenal mass proved to be a splenic rest. At short-term followup no recurrences have been noted. All patients retained sufficient adrenal cortical function to avoid steroid replacement therapy. Laparoscopic ultrasound differentiates normal adrenal parenchyma from adrenal tumors and facilitates laparoscopic partial adrenalectomy.

The von Hippel-Lindau Tumor Suppressor Stabilizes Novel Plant Homeodomain Protein Jade-1

The von Hippel-Lindau disease gene (VHL) is the causative gene for most adult renal cancers. However, the mechanism by which VHL protein functions as a renal tumor suppressor remains largely unknown. To identify low occupancy VHL protein partners with potential relevance to renal cancer, we screened a human kidney library against human VHL p30 using a yeast two-hybrid approach. Jade-1 (gene for Apoptosis and Differentiation in Epithelia) encodes a previously uncharacterized 64-kDa protein that interacts strongly with VHL protein and is most highly expressed in kidney. Jade-1 protein is short-lived and contains a candidate destabilizing (PEST) motif and plant homeodomains that are not required for the VHL interaction. Jade-1 is abundant in proximal tubule cells, which are clear-cell renal cancer precursors, and expression increases with differentiation. Jade-1 is expressed in cytoplasm and the nucleus diffusely and in speckles, where it partly colocalizes with VHL. VHL reintroduction into renal cancer cells increases endogenous Jade-1 protein abundance up to 10-fold. Furthermore, VHL increases Jade-1 protein half-life up to 3-fold. Thus, direct protein stabilization is identified as a new VHL function. Moreover, Jade-1 protein represents a novel candidate regulatory factor in VHL-mediated renal tumor suppression.

Somatic von Hippel-Lindau disease gene mutation in clear-cell renal carcinomas associated with end-stage renal disease/acquired cystic disease of the kidney.

It has been documented that renal cell carcinomas (RCCs) occur frequently in patients treated with long-term dialysis, especially in cases of end-stage renal disease (ESRD)/acquired cystic disease of the kidney (ACDK). To address the molecular pathogenesis of ESRD/ACDK-associated RCCs, we examined 14 RCCs (7 clear-cell and 7 papillary carcinomas) in patients receiving dialysis for somatic mutations of the von Hippel-Lindau disease (VHL) gene as well as of the tyrosine kinase domain of the MET oncogene. Direct sequencing analyses revealed that three tumors exhibited VHL frameshifts (618delA, 386-395del10-bp, and 723-724insTC). One of the VHL mutated tumors showed additional loss of heterozygosity at the VHL gene locus. Histopathologic and clinical data demonstrated that the three tumors having VHL mutations were clear-cell RCCs occurring in ESRD with 55, 106, and 156 months of dialysis history, respectively. We did not find any tumors with mutations in the tyrosine kinase domain of the MET. These results demonstrated that the VHL tumor-suppressor gene is also involved in a subset of clear-cell RCCs occurring in ESRD/ACDK, as in the case of sporadic clear-cell RCCs. However, mutations of the MET oncogene could not be found in the seven ESRD/ACDK-associated papillary RCCs examined.

A germline mutation in the Von Hippel-Lindau disease gene (L178Q) detected by denaturing gradient gel electrophoresis in a large Jewish-Yemenite family Communicated by: Mark H. Paalman Online Citation: Human Mutation, Mutation and Polymorphism Report #78 (1999) Online http://journals.wiley.com/1059-7794/pdf/mutation/mpr78.pdf Acknowledgments:This work was performed in partial fulfillment of the requirements for the Ph.D. degree from the Sackler School of Medicine at the

A germline mutation in the Von Hippel-Lindau disease gene (L178Q) detected by denaturing gradient gel electrophoresis in a large Jewish-Yemenite family Communicated by: Mark H. Paalman Online Citation: Human Mutation, Mutation and Polymorphism Report #78 (1999) Online http://journals.wiley.com/1059-7794/pdf/mutation/mpr78.pdf Acknowledgments:This work was performed in partial fulfillment of the requirements for the Ph.D. degree from the Sackler School of Medicine at the

A germline mutation in the von Hippel-Lindau disease gene (L178Q) detected by denaturing gradient gel electrophoresis in a large Jewish-Yemenite family.

A germline mutation in the von Hippel-Lindau disease gene (L178Q) detected by denaturing gradient gel electrophoresis in a large Jewish-Yemenite family.

Processed pseudogene from the von Hippel-Lindau disease gene is located on human chromosome 1.

The von Hippel-Lindau (VHL) disease gene is a tumor suppressor located at 3p25-26. While amplifying intron 1 of this gene, a smaller-than-expected product was found. This fragment was sequenced and was approximately 78% similar in sequence to the VHL gene and completely lacked sequence from the intron. No stop codons were found in the sequenced region. Using this DNA fragment as a probe for Northern blot hybridization analysis, no evidence was found for expression of a unique RNA. Because of the lack of intron 1 sequence and the likely lack of expression, the new sequence is most probably a part of a VHL processed pseudogene. The putative pseudogene was mapped to human chromosome band 1q12 using the polymerase chain reaction with template DNA from human/rodent somatic cell hybrids, a radiation hybrid panel, and a set of primers that were chosen to be maximally divergent from the genuine VHL gene. The human/rodent somatic cell hybrid DNAs were then used on Southern blots to determine which human bands are from the pseudogene and which are from the functional gene. This knowledge is valuable in interpreting Southern blot evidence of VHL gene abnormalities.

Germline and somatic mutations in von Hippel-Lindau disease gene and its significance in the development of kidney cancer.

Germline and somatic mutations in von Hippel-Lindau disease gene and its significance in the development of kidney cancer.

Molecular genetic mechanism of hereditary human kidney cancer development

Here we reviewed the molecular genetic mechanism in the development of 4 types of human hereditary kidney cancers. These include von Hippel-Lindau (VHL) disease, hereditary papillary renal carcinoma, familial renal cancers with translocation of chromosome 3, and Tuberous sclerosis. Loss of function of the VHL disease gene is responsible for the von Hippel-Lindau disease and major portion of sporadic clear cell renal carcinoma. Activated c-Met oncogene is responsible for the development in some cases of hereditary papillary renal cell carcinomas and sporadic papillary renal carcinomas. There are several cases of familial renal carcinoma in that translocations of chromosome 3 p are demonstrated. The molecular genetic mechanism of this disease is not known. Several reports show the development of renal cell carcinoma in Tuberous sclerosis patients. TSC 1 or TSC 2 gene may be responsible for these tumors. The detail in this disease not well known. Molecular genetic analyses for hereditary renal cancer identified several oncogenes and tumor suppressor genes in hereditary as well as sporadic renal carcinomas. Future studies may reveal new category of oncogenes or tumor suppressor genes that are involved in the human kidney cancer development.

Subcellular localization of the von Hippel-Lindau disease gene product is cell cycle-dependent.

The von Hippel-Lindau gene product (pVHL) interacts with and inhibits the cellular transcription factor elongin. However, the subcellular localization of pVHL has remained uncertain. Naturally occurring pVHL mutants which fail to interact with elongin have been described in patients with VHL disease or sporadic renal cell carcinoma (RCC). Here, we have examined the cellular expression pattern of endogenous pVHL in different RCC cell lines by immunocytochemistry and confocal microscopy. Both anti-N-terminal and anti-C-terminal pVHL antibodies were able to recognize endogenous wild-type pVHL expressed by the RCC cells studied. A C-terminal truncated VHL mutant expressed by RCC cell line A498 was detected only by the N-terminal antibody but not by the C-terminal antibody as expected. The overall staining patterns of these cell lines are similar, with a predominant nuclear speckled pattern and a moderate cytoplasmic staining in subconfluent cell cultures. Interestingly, when cells reached confluency, more prominent nuclear staining with little or no cytoplasmic expression was observed. By using double labeling with anti-VHL and anti-bromodeoxyuridine (BrdU) antibodies and cell cycle analyses, we found that in the G1/G0-phase, pVHL was localized exclusively in the nucleus associated with distinctive large subnuclear structures, whereas the majority of the cells in S-phase of the cell cycle also showed a diffuse cytoplasmic staining. Our results indicate that subcellular localization of pVHL is regulated in a cell cycle-dependent manner.

Pheochromocytoma in von Hippel-Lindau Disease: Clinical Presentation and Mutation Analysis in a Large, Multigenerational Kindred1

The clinical presentation and characterization of the mutation in members of a large kindred with von Hippel-Lindau disease (VHLD) and pheochromocytoma were examined. Twenty-five proven cases of VHLD occurring in four generations of a large kindred have been followed since 1964, and pheochromocytoma has occurred in 17. Symptoms of pheochromocytoma developed at an early age, on average at 12.5 +/- 1.3 yr, and definitive diagnosis and treatment of pheochromocytoma occurred at 19.9 +/- 2.6 yr. Significantly higher urine catecholamine concentrations were observed in younger patients than in older ones. Mutation analysis was performed in 14 family members, and a new mutation in the VHLD gene was identified in 11; this mutation is a G to T change at nucleotide 658 that results in the substitution of a serine for an alanine residue at position 149 of the polypeptide chain. Seven of the 11 patients with the mutation have VHLD; four, all 10 yr old or less, are asymptomatic and have no evidence of disease, but are at high risk for developing VHLD. These children are being followed closely for clinical and biochemical manifestations. The characterization of this new mutation has permitted identification of family members who are likely to develop VHLD.

Somatic Mutation of the Tuberous Sclerosis (Tsc2) Tumor Suppressor Gene in Chemically Induced Rat Renal Carcinoma Cell

Purpose von Hippel-Lindau (VHL) gene mutations are detected in noninherited, sporadic human renal cell carcinomas (RCs) at a high frequency. We recently identified a germline mutation in the rat homologue of the human tuberous sclerosis (TSC2) predisposing RC gene in the Eker rat model, and in this study we searched for mutations of the Tsc2 gene in chemically induced non-Eker rat RCs. Materials and Methods Chemically [N-ethyl-N-hydroxyethylnitrosamine (EHEN)]-induced non-Eker rat RC lines (designated as BP13 and BP36B) were subjected to PCR-single strand conformation polymorphism (PCR-SSCP) analysis using specific primers covering entire exons of Tsc2 gene (41 coding exons and one non-coding exon). We simultaneously searched for mutations of Vhl gene, a rat homologue of von Hippel-Lindau disease gene (VHL) as well as Tsc2 gene. Results BP36B showed an abnormal mobility shift from the normal tissue of the same rat in exon 35 on analysis by PCR-SSCP. This mutation was confirmed by direct sequencing and found to be a T-to-C transition at the second position of codon 1470, resulting in an amino acid change from leucine to proline (missense mutation). Conclusions This is the first demonstration of Tsc2 gene somatic mutation in non-Eker rat RCs. Our present findings call attention to further investigation of the role of Tsc2 gene mutations in rat renal carcinogenesis and possible Tsc2 gene mutations in human RCs, especially of the non-clear cell type, which are not related to the VHL gene.

MUTATIONAL STATE OF P16/CDKN2 AND VHL GENES IN SQUAMOUS-CELL CARCINOMA OF THE ORAL CAVITY

Two new tumor-suppressor genes, the cyclin dependent kinase 4 inhibitor gene (p16/CDKN2) and the von Hippel-Lindau disease gene (VHL), have been cloned and mapped on chromosomes 9p and 3p respectively, where putative tumor-suppressor genes of the oral squamous-cell carcinoma (SCC) may be present. In order to elucidate whether abnormalities of these genes could contribute to the tumorigenesis of oral SCC, genomic DNAs from 62 tissue samples of tumors (32 primary SCCs and 30 pre-cancerous lesions) and from 7 oral SCC cell lines were examined by polymerase chain reaction-single strand conformation polymorphism analysis and direct DNA sequencing. Four of 7 (57%) cell lines contained nonsense mutations or missense mutations in the p16/CDKN2 gene and 2 of 32 (6%) primary oral SCCs had nonsense mutations. Particularly, 3 of 4 nonsense mutations detected in the present study were found in codon 80 (CGA-->TGA; Arg-->Stop), suggesting that codon 80 was a mutational hot spot of the p16/CDKN2 gene. No VHL gene mutation was found in any subject. These results suggest that mutation of the VHL gene is not a common factor in the development of human oral SCC. In contrast, the p16/CDKN2 gene may be correlated with the progression of a subtype of this cancer.

Von hippel-lindau disease: New strategies in early detection and treatment

Von Hippel-Lindau disease is an autosomal dominant inherited disorder causing hemangioblastomas of the central nervous system (CNS), retinal hemangiomas, renal cell carcinomas, pheochromocytomas, pancreatic and liver cysts, and epididymal cystadenomas. purpose: Since 1976, we have periodically screened for the lesions in a large affected family and were able to evaluate new strategies in detection and treatment. patients and methods: A total of 23 individuals underwent the screening program. A multi-disciplinary team of physicians was involved. results: In 13 patients (7 females and 6 males), a total of 31 tumors was detected; hemangioblastoma of the CNS (9), retinal angioma (4), renal involvement (8), pheochromocytoma (4), pancreatic lesions (4), and liver lesions (2) were diagnosed by periodic family screening. On the basis of more than 10 years of experience and current literature, new criteria for diagnosis and treatment have been proposed. conclusion: The von Hippel-Lindau disease gene appears to be a tumor suppressor gene, and its absence or a defect in its structure is responsible for the predisposition to the disease. Tumor development depends on a somatic second mutation in the homologous allele. That means, in disease-gene carriers, tumor growth may begin at any age. Most of the lesions can be treated successfully when diagnosed in time. Periodic screening by a multidisciplinary team has to be continued lifelong.

Genetic alterations in sporadic renal-cell carcinoma: molecular analyses of tumor suppressor gene harboring chromosomal regions 3p, 5q, and 17p.

On a genetic level, renal-cell carcinoma has been characterized by an abnormality on the short arm of chromosome 3 (3p), which suggests the inactivation of a tumor suppressor gene. One tumor suppressor gene at 3p, the von Hippel-Lindau disease gene, is implicated in tumor development of a whole spectrum of hereditary neoplasms, including renal-cell carcinoma. It is not clear whether the same tumor suppressor gene accounts for all, i.e., hereditary and sporadic, renal-cell carcinomas. Analysis of 28 patients with sporadic renal-cell carcinomas for loss of heterozygosity was performed at chromosomal regions that contain known tumor suppressor genes so as to assess their potential involvement during renal tumorigenesis. We focused on chromosome 3p because it contains the von Hippel-Lindau (VHL) disease gene, on 5q because it harbors tumor suppressor genes involved in colorectal carcinoma, and on 17p because it includes a tumor suppressor gene involved in breast, colon, and lung carcinoma. Loss of alleles at 3p affected 96% of the evaluable patients, with frequencies being highest in the VHL region in 3p25-26 and at loci in 3p21. These data confirm the importance of a 3p defect early during tumorigenesis; however, the question as to the existence of a second renal-cell carcinoma gene remains unresolved. Changes at 5q were 53% and those at 17p were 35%, suggesting that these loci may not contribute to the initiation of the disease but rather may represent accumulating genetic defects associated with progression and malignancy.

Molecular genetic investigations of the mechanism of tumourigenesis in von Hippel-Lindau disease: analysis of allele loss in VHL tumours

Von Hippel-Lindau (VHL) disease is a dominantly inherited familial cancer syndrome characterised by the development of retinal and central nervous system haemangioblastomas, renal cell carcinoma (RCC), phaeochromocytoma and pancreatic tumours. The VHL disease gene maps to chromosome 3p25-p26. To investigate the mechanism of tumourigenesis in VHL disease, we analysed 24 paired blood/tumour DNA samples from 20 VHL patients for allele loss on chromosome 3p and in the region of tumour suppressor genes on chromosomes 5, 11, 13, 17 and 22. Nine out of 24 tumours showed loss of heterozygosity (LOH) at at least one locus on chromosome 3p and in each case the LOH included the region to which the VHL gene has been mapped. Chromosome 3p allele loss was found in four tumour types (RCC, haemangioblastoma, phaeochromocytoma and pancreatic tumour) suggesting a common mechanism of tumourigenesis in all types of tumour in VHL disease. The smallest region of overlap was between D3S1038 and D3S18, a region that corresponds to the target region for the VHL gene from genetic linkage studies. The parental origin of the chromosome 3p25-p26 allele loss could be determined in seven tumours from seven familial cases; in each tumour, the allele lost had been inherited from the unaffected parent. Our results suggest that the VHL disease gene functions as a recessive tumour suppressor gene and that inactivation of both alleles of the VHL gene is the critical event in the pathogenesis of VHL neoplasms. Four VHL tumours showed LOH on other chromosomes (5q21, 13q, 17q) indicating that homozygous VHL gene mutations may be required but may not be sufficient for tumourigenesis in VHL disease.