If the presence of pheochromocytomas is regarded as a phenotypic marker for VHL classification, the mutations found in 22 VHL patients without pheochromocytoma consisted of 11 missense mutations, six microdeletions or insertions, two splice-site alterations and three deletions. The mutations found in ...
2.5 Positive clinical predictive value (life-time risk of developing the disease if the test is positive) Penetrance by age of 65 years is 490%, depending upon the specific VHL phenotypic manifestation. VHL patients may present with a variety of tumors affecting eye, central nervous system, ...
This aspect could be explained by the low penetrance of this variant, both with respect to late disease onset and predisposition to benign tumours. In fact, there is a large variability in the age onset of this disorder, and environmental factors and genetic modifiers influence the phenotypic ...