Genotype Phenotype Correlation in Asian Indian Von Hippel-Lindau (VHL) Syndrome Patients with Pheochromocytoma/paraganglioma

The data in genotype-phenotype correlation in Indian von Hippel-Lindau (VHL) patients is limited. We have retrospectively studied 31 genetically proven VHL patients with pheochromocytoma/paraganglioma (PCC/PGL) from families and have reviewed the World literature on PCC/PGL in patients with large VHL deletions. Three patients had large deletions and 28 patients had other mutations [missense mutations in 25, 3 bp deletion in 2 and single bp duplication in one]. Unilateral PCC were significantly more common in patients with large VHL deletions whereas multiple PCC (bilateral PCC or PCC + sympathetic PGL) were significantly more common in those with other mutations. World literature review confirmed the rarity of PCC/PGL in patients with large deletions and we report the first definitive case of PCC associated with complete VHL deletion. Pancreatic neuroendocrine tumours were more common, often metastatic and the most common cause of death in our cohort. Our study had eight parent off-spring pairs from five families. The off-springs were significantly younger at presentation and had significantly higher number of PCC/PGL. In conclusion, PCC/PGL are rare in patients with large VHL deletions and if occur are most likely to be solitary. Patients with bilateral PCC or multifocal PCC/PGL are least likely to have large VHL deletions. Our study also provides additional evidence for existence of the phenomenon of anticipation in VHL syndrome.