Molecular analysis of the Von Hippel-Lindau (VHL) gene in a family with non-syndromic pheochromocytoma: the importance of genetic testing.

The two index patients of the family analyzed in this study had undergone bilateral adrenalectomy for pheochromocytomas. This prompted genetic analyses of the probands and seven first-degree relatives. The two pheochromocytoma patients and two additional asymptomatic family members were found to harbor a mutation c496G>T in exon 3 of the VHL gene. The family was then lost to systematic follow-up. Three years after performing the initial genetic evaluation, the sister of the probands, who was known to carry the same VHL germline mutation, was referred to our service after a pregnancy that was complicated by preeclampsia. She reported paroxysms suggestive for pheochromocytoma, but her urinary metanephrines were negative. However, computerized tomography of the abdomen showed an adrenal mass that was also positive on metaiodobenzylguanidine (MIBG) scintigraphy. This study illustrates that molecular analysis of the index patient(s) can lead to the identification of presymptomatic relatives carrying the mutation. Moreover, despite negative urinary metanephrines, the identification of a specific mutation has led to an increased suspicion and detection of a pheochromocytoma in the sister of the probands.