Comprehensive characterization and building of National Registry of von Hippel-Lindau disease in Brazil

BACKGROUND: Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder caused by pathogenic variants in VHL gene. The common manifestations include hemangioblastomas (HB) of the central nervous system (CNS) and retina (RH); pheochromocytoma (PHEO); clear cell renal cell carcinoma (ccRCC); pancreatic and renal cysts (PRC) and pancreatic neuroendocrine neoplasm (PNEN). METHODS: The first characterization of VHL in Brazil was published in 2003 and included 20 families with a history of VHL. The aim of this study was to expand the previous Brazilian cohort to include more families, as well as to collect prospectively both clinical and molecular characteristics of patients with VHL to build the VHL Brazilian Registry (VHLBR). Patients with VHL were selected through review of data from medical records of experts and from social networks of support for families with VHL in Brazil. RESULTS: A total of 142 subjects representing 62 unrelated Brazilian families with VHL were registered. The mean age of VHL onset was 28.78 years old and 128 individuals (90.1%) had at least one VHL-related lesion. CNS HB was the most common manifestation occurring in 91 (71%) patients, followed by multiple PRC (48.4%), RH (39.8%), ccRCC (28.9%), PHEO (12.5%) and PNEN (7.8%). Of the 97 subjects whose presence of VHL variants was confirmed, 51 (52.6%) had missense variants, 22 (22.7%) large deletions, 10 (10.3%) frameshift, 7 (7.2%) splice site, 4 (4.1%) nonsense and 3 (3.1%) in-frame deletions. Regarding surveillance, 115 (81%) participants had at least one physician responsible for their outpatient follow-up; however, 69 (60%) of them did not report a regular frequency of tests. CONCLUSION: We built the largest prospective VHLBR with organized collections of clinical and genetic data from families with VHL, which will be helpful to guide policies for VHL care and oncogenetics in Brazil. Although there have been improvements in diagnosis and clinical screening methods, VHL care in Brazil is still deficient, especially regarding surveillance and regular medical appointments with experts.