Germline mutation of Glu70Lys is highly frequent in Korean patients with von Hippel–Lindau (VHL) disease

Investigation of germline VHL variants in Iranian patients with retinal capillary hemangioblastoma and genotype-phenotype analysis

BACKGROUND

Retinal capillary hemangioblastoma (RCH), while sporadic in some cases, is the most common and earliest manifestation of von Hippel-Lindau disease (VHL). This is the first report on different types of VHL variants and genotype-phenotype correlations in Iranian families with RCH.

MATERIALS AND METHODS

In this prospective observational case series study, 17 families with RCH were included. PCR was performed to amplify 3 exons of VHL gene. Afterward, Sanger sequencing was performed on all PCR products. For the detection of VHL copy number variations, MLPA was used.

RESULTS

Our study identified 10 different types of VHL variants. Missense mutations were the most common variants found and affected the structure of α domain of the VHL protein (pVHL). The majority of mutations (72.7%) in the patients with RCH and central nervous system hemangioblastoma (CNS-HB) were located on α domain.

CONCLUSION

α domain of VHL may play a potential role in the pathogenesis of RCH. Our findings suggest that genotype-phenotype characteristics in those variants in α- domain may predispose patients to RCH with CNS-HB.

Clinical and Genetic Characteristics of Retinal Capillary Hemangioblastoma in Korean Patients

PURPOSE

We investigated the clinical features of Korean patients with retinal capillary hemangioblastoma (RCH) and genetic variants of the von Hippel-Lindau (VHL) gene.

METHODS

A retrospective analysis was performed on patients with RCH from 2003 to 2021 at Seoul National University Bundang Hospital. Sporadic and hereditary RCH associated with VHL disease were classified based on the specific tumors and family history. Clinical features, including the location and number of RCH and bilateral involvement, were investigated. Multiplex ligation-dependent probe amplification and direct sequencing targeting the VHL gene were performed for six RCH cases associated with VHL disease.

RESULTS

A total of 18 patients (23 eyes) were enrolled in this study. The mean age at diagnosis was 37 ± 15 years. Twelve patients had hereditary RCH associated with VHL disease, and six patients had sporadic RCH. All five patients with bilateral RCH were clinically diagnosed with VHL disease, and 13 patients had unilateral RCH. Juxtapapillary RCH was only observed in patients with VHL. The most common complication of RCH was the epiretinal membrane, followed by the subretinal fluid. Pathogenic variants were identified in four patients. All three patients with type 1 VHL had the well-known missense mutation p.Glu70Lys, and one patient with type 2 VHL had the nonsense mutation p.Trp88Ter.

CONCLUSIONS

In Korean patients with RCH, bilateral involvement and juxtapapillary RCH are highly likely to be associated with VHL disease. Because RCH may be the first clinical manifestation in patients with VHL, active genetic testing of the VHL gene and systemic evaluation are required.

Von Hipple-Lindau disease complicated with central retinal vein occlusion: a case report

Background

Central Retinal Vein Occlusion (CRVO) is a rare complication of von Hipple-Lindau (VHL) disease. This report presents the first case of VHL disease complicated with CRVO caused by VHL c.208G > A mutation.

Case presentation

A 20 s man whose left eye visual acuity gradually declined for half a year. The visual acuity of the left eye is counting fingers. Fundus examination revealed that retinal hemangioblastoma was also found in addition to typical CRVO signs such as tortuous expansion of retinal veins and flame-shaped hemorrhage of the retina. Liver tumor, cerebral infarction and erythrocytosis were found during systemic examination, and the diagnosis of polycythemia was confirmed by bone marrow smear. Furthermore, both family history and genetic analysis indicated that the patient had VHL disease caused by VHL c.208G > A. In this patient, a large number of bone marrow erythrocytes proliferated due to VHL disease, which led to the increase of blood viscosity and erythrocyte vascular adhesion, resulting in the obstruction of central retinal vein blood flow, and finally CRVO. For CRVO and its pathogenic factor polycythemia, patient received laser retinal photocoagulation and phlebotomies. After a 1-year follow-up, the vision in the left eye improved to 0.2 logMAR.

Conclusions

This is a rare case of polycythemia complicated by CRVO in patient with VHL disease. It reminds us that the systemic disease factors should be fully considered in the diagnosis of young patients with CRVO, and that treatment requires a coordinated effort of physicians.

Genetic Counseling and Long-Term Surveillance Using a Multidisciplinary Approach in von Hippel-Lindau Disease

Background

von Hippel–Lindau (VHL) disease is an autosomal dominant disorder caused by variants of the VHL tumor suppressor gene (VHL). Early detection and treatment are essential to prevent morbidity and mortality. We evaluated the effectiveness of surveillance strategies and the utility of a VHL clinic with a multidisciplinary team for the first time in Korea.

Methods

The VHL clinic was organized at the Samsung Medical Center in 2011 and consisted of a multidisciplinary team, including an endocrinologist, urologist, general surgeon, neurosurgeon, ophthalmologist, otolaryngologist, and radiologist. Biochemical and imaging surveillance and personalized genetic counseling were conducted at the VHL clinic and patients were referred to the necessary departments upon detection of disease manifestation. We divided the patients in three groups (I–III) based on their compliance to VHL clinic attendance.

Results

Between 2011 and 2018, 50 VHL patients were identified by VHL molecular analysis and referred to the VHL clinic. Most patients regularly participated in imaging of the central nervous system (43/50, 86.0%) and of the abdomen (46/50, 92.0%). However, there were differences in compliance to determination of the catecholamine level, audiometry, and ophthalmic examination among the three groups.

Conclusions

We present the results of using a multidisciplinary team approach and showed that the VHL clinic strategy is useful for the comprehensive surveillance and management of VHL disease. We hope that VHL clinics will be widely set up in hospitals to improve prognosis in patients with VHL.

The Role of VHL in the Development of von Hippel-Lindau Disease and Erythrocytosis

Von Hippel-Lindau disease (VHL disease or VHL syndrome) is a familial multisystem neoplastic syndrome stemming from germline disease-associated variants of the VHL tumor suppressor gene on chromosome 3. VHL is involved, through the EPO-VHL-HIF signaling axis, in oxygen sensing and adaptive response to hypoxia, as well as in numerous HIF-independent pathways. The diverse roles of VHL confirm its implication in several crucial cellular processes. VHL variations have been associated with the development of VHL disease and erythrocytosis. The association between genotypes and phenotypes still remains ambiguous for the majority of mutations. It appears that there is a distinction between erythrocytosis-causing VHL variations and VHL variations causing VHL disease with tumor development. Understanding the pathogenic effects of VHL variants might better predict the prognosis and optimize management of the patient.

Pheochromocytomas and paragangliomas in von Hippel-Lindau disease: not a needle in a haystack

OBJECTIVE

Pheochromocytomas are a hallmark feature of von Hippel-Lindau disease (vHL). To our knowledge, this is the first systematic review with meta-analysis evaluating the frequency of pheochromocytomas and/or paragangliomas (PPGLs) in patients with vHL, as well as among patients with different vHL subtypes.

DESIGN

Systematic review with meta-analysis.

METHODS

We searched on MEDLINE, Scopus, and Web of Science. We included primary studies assessing participants with vHL and reporting on the frequency of PPGL. We performed random-effects meta-analysis to quantitatively assess the frequency of PPGL, followed by meta-regression and subgroup analysis. Risk of bias analysis was performed to assess primary studies' methodological quality.

RESULTS

We included 80 primary studies. In 4263 patients with vHL, the pooled frequency of PPGL was 19.4% (95% CI = 15.9-23.6%, I2 = 86.1%). The frequency increased to 60.0% in patients with vHL type 2 (95% CI = 53.4-66.3%, I2 = 54.6%) and was determined to be of 58.2% in patients with vHL type 2A (95% CI = 49.7-66.3%, I2 = 36.2%), compared to 49.8% in vHL type 2B (95% CI = 39.9-59.7%, I2 = 42.7%), and 84.1% in vHL type 2C (95% CI = 75.1-93.1%, I2 = 0%). In meta-regression analysis, more recent studies were associated with a higher frequency of PPGL. All studies had at least one internal validity item classified as 'high risk of bias,' with 13% studies having low risk of bias in all external validity items.

CONCLUSIONS

PPGLs are a common manifestation of vHL. Despite methodological limitations and differences across primary studies, our results point to the importance of PPGL screening in patients with vHL.

Frequent Mutations of VHL Gene and the Clinical Phenotypes in the Largest Chinese Cohort With Von Hippel-Lindau Disease

Von Hippel–Lindau (VHL) disease is a rare autosomal-dominant inherited tumor syndrome. We aimed to analyze the correlations between frequent VHL mutations and phenotypes in Chinese VHL families. We screened 540 patients from 187 unrelated Chinese VHL families for 19 frequent VHL mutations. The penetrance and mean age at onset for VHL-associated susceptible organs were calculated and compared. The overall survival of VHL patients was described with Kaplan–Meier curves. Among the 19 frequent germline mutations, there were four hotspot mutation sites (194, 481, 499, and 500). Missense mutations were the most common types of mutations (70.0%) followed by nonsense mutations (20.0%) and splicing mutations (10.0%). Due to the diversity of these mutations, the penetrance for each organ and the age at onset are distinct. Even in cases of similar mutations, variance in the penetrance and age at onset was observed. The mean age at death for the patients in this cohort was 42.4 ± 13.5 years, and variability was observed in the Kaplan–Meier curves. We present a precise summary of the phenotypes for the frequent VHL mutations in the largest Chinese VHL cohort, which provides valuable strategies for genetic counseling and clinical surveillance of VHL individuals.

von Hippel-Lindau development in children and adolescents

The autosomal dominant von Hippel-Lindau disease (vHL) is associated with a lifelong risk of tumor development, especially retinal and CNS hemangioblastomas, pheochromocytoma, and renal cell carcinoma. Knowledge of paediatric vHL development is limited, and current surveillance guidelines are based on expert opinions. We aimed to describe the course of vHL development in children and adolescents, focusing on age at first manifestation, manifestation frequencies, and types. The prevalence of vHL diagnosis as well as manifestations in childhood were evaluated based on 99 patients, who had started surveillance before 18 years: 37 Danish patients from the national vHL research database and 62 international patients reported in 15 articles. Overall, 70% (69 of 99) developed manifestations before 18 years (median age at first manifestation: 12 years (range: 6-17 years)). Thirty per cent (30 of 99) had developed more than one manifestation type; the most frequent were retinal (34%) and CNS (30%) hemangioblastomas. Among the 37 Danish patients, 85% (97 of 116) of their tumors were asymptomatic. Vision outcome is significantly improved in hemangioblastomas that are treated while still asymptomatic. We agree with current guidelines that retinal surveillance be performed from birth. The patients had their first CNS hemangioblastomas at the median ages of 13-14 years (range: 6-17 years). Further, 11% (4 of 37) of the Danish patients had CNS surgery in their teenage years. Although the cohort is too small to make definite conclusions about specific initiation ages, regular CNS surveillance from vHL patients' teenage years seems clinically relevant.

Genotype-phenotype analysis of von Hippel-Lindau syndrome in Korean families: HIF-α binding site missense mutations elevate age-specific risk for CNS hemangioblastoma

BACKGROUND

von Hippel-Lindau (VHL) disease is a rare hereditary tumor syndrome caused by VHL gene mutations that is characterized by heterogeneous phenotypes such as benign/malignant tumors of the central nervous system, retina, kidney, adrenal gland, and pancreas. The genotype-phenotype correlation has not been well characterized in the Korean population so far. Therefore, this study aimed to evaluate the VHL mutation spectrum and genotype-phenotype correlations in Korean VHL patients.

METHODS

Thirteen unrelated subjects with VHL mutations were included. Direct sequencing and multiplex ligation-dependent probe amplification were performed. Consequently, the clinical manifestations and family histories of the subjects were evaluated.

RESULTS

We identified 10 different VHL mutations. The c.160_161delAT frameshift mutation was novel. Missense mutations clustered in 2 domains (α domain in exon 1; β domain in exon 3). The most frequently observed mutation was c.208G > A (p.Glu70Lys). Milder phenotypes were observed in subjects with de novo mutations. Age-specific risk for CNS hemangioblastoma was significantly higher in subjects carrying missense mutations within the HIF-α binding site (P < 0.05).

CONCLUSIONS

This study provides insight into the genotype-phenotype correlation in that amino acid substitutions in the HIF-α binding site may predispose patients to age-related risks of CNS hemangioblastoma.

Germline mutations in the VHL gene associated with 3 different renal lesions in a Chinese von Hippel-Lindau disease family

Von Hippel-Lindau (VHL) disease is a rare autosomal dominant inherited cancer syndrome that is characterized by hemangioblastomas in the central nervous system and retina, renal cell carcinoma and cysts, pancreatic tumors and cysts, and pheochromocytoma. The underlying gene in this disease is the VHL tumor suppressor gene. We characterized a family with 2 affected siblings. The brother and sister displayed VHL type 2B and type 2A features, respectively. Renal lesions in the brother exhibited 3 different phenotypes, including simple renal cysts, multilocular cystic renal cell carcinoma and clear cell renal cell carcinoma. The phenotypes of the 3 concurrent renal lesions were first reported in this study. Mutation detection of the VHL gene revealed 2 recurrent mutations, namely c.256C>T (p.P86S) and c.340 + 5G > C. The former was predicted to be deleterious and to destabilize the hydrophobic core and lead to VHL dysfunction; however, the latter was predicted to be a benign variant. Our findings provided new data for the genotype-phenotype of VHL diseases and elucidated the pathogenic mechanism with in silico analysis.