One hundred and sixteen unrelated VHL disease patients have been investigated by molecular genetic analysis. Twenty-two of these were previously shown to have germline deletions on Southern analysis, and in the present study the remaining 94 patients were screened for intragenic mutations via SSCP and heteroduplex analysis of 855 bp of the VHL coding sequence and 800 bp of the 3' UTR. An intragenic mutation was identified in 55 (59%) out of 94 patients without germline deletions on Southern analysis. In all patients with multiple affected family members the missense mutation segregated with the disease. Large deletions or intragenic mutations predicted to cause a truncated protein were found in 36 of 53 families without pheochromocytoma (VHL type 1) and 2 of 12 families with pheochromocytoma (VHL type 2). This study also investigated the frequency of different mutation classes between kindreds with and without pheochromocytoma. The L153Cfs*6 (c.457del) deletion (noted as p.224fs (c.670delC) in the paper due to a difference in reference transcript used) was found in at least one patient in kindred 41, and at least one patient in kindred 99. Pheochromocytoma was not observed in any members of kindred 41 (implying the affected patient(s) had VHL disease type 1). No familial phenotypic information could be inferred from the paper for kindred 99.

One hundred and sixteen unrelated VHL disease patients have been investigated by molecular genetic analysis. Twenty-two of these were previously shown to have germline deletions on Southern analysis, and in the present study the remaining 94 patients were screened for intragenic mutations via SSCP and heteroduplex analysis of 855 bp of the VHL coding sequence and 800 bp of the 3' UTR. An intragenic mutation was identified in 55 (59%) out of 94 patients without germline deletions on Southern analysis. In all patients with multiple affected family members the missense mutation segregated with the disease. Large deletions or intragenic mutations predicted to cause a truncated protein were found in 36 of 53 families without pheochromocytoma (VHL type 1) and 2 of 12 families with pheochromocytoma (VHL type 2). This study also investigated the frequency of different mutation classes between kindreds with and without pheochromocytoma. The L153Cfs*6 (c.457del) deletion (noted as p.224fs (c.670delC) in the paper due to a difference in reference transcript used) was found in at least one patient in kindred 41, and at least one patient in kindred 99. Pheochromocytoma was not observed in any members of kindred 41 (implying the affected patient(s) had VHL disease type 1). No familial phenotypic information could be inferred from the paper for kindred 99.