21 missense mutations
Among patients prospectively followed by the members of the French VHL Study Group, 35 consecutive patients with well-documented endocrine pancreatic tumour (20 women and 15 men; median age,37 [21Y-57] years) were included. All 35 patients had VHL germline mutations and were assessed for the presence of pheochromocytoma and renal carcinoma in addition to pancreatic tumours. The presence of other phenotypes was not described. DNA was isolated from peripheral blood lymphocytes and mutations were detected using direct sequencing of the 3 exons of VHL and/or southern blot analysis. A germline missense mutation (c.256C>T) was found in 3 patients, 2 of which were related. Patient No 7 from family 503 presented with pancreatic endocrine tumour, pheochromocytoma, and renal carcinoma and patient No 15 from family 503 presented with pancreatic endocrine tumour. Their familial relation was not described. Patient No. 27 from family 11 also had the same mutation and presented with pancreatic endocrine tumour, pheochromocytoma, and renal carcinoma. The patients' phenotypes are highly specific to VHL disease (ACMG PP4).