Study comparing two types of screening provision for people with von Hippel-Lindau disease

von Hippel-Lindau disease: Updated guideline for diagnosis and surveillance

von Hippel Lindau disease (vHL) is caused by a hereditary predisposition to multiple neoplasms, especially hemangioblastomas in the retina and CNS, renal cell carcinomas (RCC), pheochromocytomas, neuroendocrine pancreatic tumours (PNET) and endolymphatic sac tumours. Evidence based approaches are needed to ensure an optimal clinical care, while minimizing the burden for the patients and their families. This guideline is based on evidence from the international vHL literature and extensive research of geno- and phenotypic characteristics, disease progression and surveillance effect in the national Danish vHL cohort. We included the views and preferences of the Danish vHL patients, ensured consensus among Danish experts and compared with international recommendations. RECOMMENDATIONS: vHL can be diagnosed on clinical criteria, only; however, in most cases the diagnosis can be supported by identification of a pathogenic or likely pathogenic variant in VHL. Surveillance should be initiated in childhood in persons with, or at risk of, vHL, and include regular examination of the retina, CNS, inner ear, kidneys, neuroendocrine glands, and pancreas. Treatment of vHL manifestations should be planned to optimize the chance of cure, without unnecessary sequelae. Most manifestations are currently treated by surgery. However, belzutifan, that targets HIF-2α was recently approved by the U.S. Food and Drug Administration (FDA) for adult patients with vHL-associated RCC, CNS hemangioblastomas, or PNETs, not requiring immediate surgery. Diagnostics, surveillance, and treatment of vHL can be undertaken successfully by experts collaborating in multidisciplinary teams. Systematic registration, collaboration with patient organisations, and research are fundamental for the continuous improvement of clinical care and optimization of outcome with minimal patient inconvenience.

Unintended diagnosis of Von Hippel Lindau syndrome using Array Comparative Genomic Hybridization (CGH): counseling challenges arising from unexpected information

Array Comparative Genomic Hybridization (array CGH) is a powerful tool for identifying genomic imbalances and providing a diagnosis in individuals with a normal karyotype. It has been particularly useful in the investigation of individuals with developmental delay +/-, dysmorphic features and/or multiple congenital abnormalities. However, this non-targeted method of scanning the whole genome can reveal unexpected information. We present a case where array CGH identified the cause of a proband's moderate mental retardation by discovery of a de novo deletion of chromosome 3p25.3. This deletion was shown to contain at least 25 genes including the VHL gene, the deletion or mutation of which leads to Von Hippel Lindau (VHL) syndrome. Presymptomatic testing for VHL is usually offered after appropriate genetic counseling about the implications of this condition. Therefore, scanning the genome by array CGH presents a number of challenges for the genetic counselor. We suggest that further understanding of the psychosocial effects of array CGH is needed in order for appropriate pre- and post-test counseling to be provided.

Genetics of chromaffin tumors

The old term of 'chromaffin tumors' encompasses both pheochromocytomas (PHs) and paragangliomas (PGLs). The identification of SDHx genes - new mitochondrial tumor-suppressor genes involved in hypoxia/angiogenesis pathways causing hereditary PGL/PH syndromes - has dramatically changed the genetics of chromaffin tumors. Between 25 and 30% of PGLs/PHs are inherited and are caused by a germline mutation in one of the six susceptibility genes (NF1, RET, VHL, SDHD, SDHB and SDHC). All patients with PGLs/PHs should, therefore, attend genetic counsultations. Genetic testing can be targeted according to family and clinical history. The identification of an inherited disease modifies the management and follow-up of index case and provides an opportunity for predictive genetic testing for other family members.