Genotype-phenotype correlation in ocular von Hippel-Lindau (VHL) disease: the effect of missense mutation position on ocular VHL phenotype.

PURPOSE von Hippel-Lindau (VHL) disease is a dominantly inherited, multisystemic tumor syndrome caused by mutations in the VHL gene. This study was conducted to establish genotype-phenotype correlations between the positions of disease-causing missense mutations and the ocular phenotypes of VHL disease. METHODS Participants with clinically defined VHL disease and documented germline missense mutations in the VHL gene were identified in a cross-sectional study (n=412). Statistical analysis was used to correlate the position of the missense mutation in either the alpha- or beta-domain of the VHL protein with the ocular disease phenotype. RESULTS Missense mutations among study participants were located in 47 of the 213 possible codons in the VHL gene. Almost all mutations (98.5%) were located in one of two structural domains of the VHL protein: the alpha- and beta-domains. alpha-Domain mutations were significantly associated with a higher prevalence of retinal capillary hemangioblastomas (RCHs) compared with the beta-domain mutations (P=0.016). Among patients with RCHs, the prevalence of the lesions in the juxtapapillary position was also significantly higher in patients with alpha-domain mutations (P=0.0017). Conversely, beta-domain mutations correlated with a higher prevalence of peripherally located RCHs (P=0.0104). CONCLUSIONS The location of missense mutations in the VHL gene correlates significantly with the prevalence and phenotype of ocular disease, and as such, influences the risk of visual loss in affected patients. These genotype-phenotype correlations can assist in the prognostic counseling and follow-up of VHL patients and may provide a basis for molecular inferences on ocular VHL disease pathogenesis.