A novel missense mutation (N78D) in a family with von Hippel-Lindau disease with central nervous system haemangioblastomas, pancreatic and renal cysts

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.

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.