Between 1994 and 2001, the Dutch VHL working group conducted DNA analysis on 146 probands with VHL-associated manifestations. DNA of probands was extracted from peripheral blood samples. Exons 1, 2 and 3 of the VHL gene and their flanking untranslated and intronic coding sequences were amplified by PCR and subjected to semi-automated sequence analysis. Screening for structural rearrangements, including deletions, involving the VHL gene was performed by Southern blot analysis and the multiplex ligation-dependent probe amplification (MLPA) assay. Deletions encompassing the entire VHL gene were confirmed by FISH analysis on lymphocytes from affected individuals. VHL mutations were identified in 43 families. This delins (c.393_394delinsA) mutation was found in two VHL type 1 family members (family no. 26). Both had retinal hemangioblastomas, one had renal cysts and one had pancreatic cysts.