Intended use: The SALSA MLPA probemix P016 VHL is an in vitro diagnostic (IVD)¹ or a research use only (RUO) assay for the detection of deletions in the human VHL gene in order to confirm a potential cause and clinical diagnosis for Von Hippel-Lindau syndrome (VHL). This product can also be used for molecular genetic testing of at-risk family members. This assay is for use with human DNA extracted from peripheral blood.

Most defects in the VHL gene are point mutations, which will not be detected by MLPA. It is therefore recommended to use this SALSA MLPA probemix in combination with sequence analysis of VHL. Copy number changes detected by only a single probe always require validation by another method. This probemix is not intended to be used as a standalone assay for clinical decisions. The results of this test must be interpreted by a clinical molecular geneticist or equivalent.

¹Please note that this probemix is for In Vitro Diagnostic use (IVD) in the countries specified at the end of this product description. In all other countries, the product is for Research Use Only (RUO).

Clinical background: Von Hippel-Lindau (VHL) syndrome is a dominantly inherited familial cancer syndrome predisposing to a variety of malignant and benign neoplasms, most frequently retinal, cerebellar and spinal hemangioblastoma, renal cell carcinoma, pheochromocytoma, and pancreatic tumours. The basis of familial inheritance of VHL is a germline mutation in the VHL tumour suppressor gene, located in chromosomal region 3p25.3. 80% of individuals with VHL syndrome inherit a mutation whereas 20% of individuals have a de novo mutation (Gene Reviews; http://www.ncbi.nlm.nih.gov/books/NBK1463/). Of the mutations in the VHL gene, 30-60% are missense mutations, 20-40% large intragenic deletions (0.5-250 kb), 12-20% microdeletions or insertions and 7-11% nonsense mutations (Decker et al. 2014). Interestingly, the loss of the nearby BRK1 (C3orf10/HSPC300) gene in combination with VHL loss is associated with a reduced risk of renal cell carcinoma as compared to defects in the VHL gene only (Escobar et al. 2010, McNeill et al. 2009). This probemix contains two probes that target the BRK1 gene. This probemix has been used in a research setting to detect VHL deletions in tumour tissue (Banks et al. 2006, Patard et al. 2009, Young et al. 2009).

Probemix content: The SALSA MLPA Probemix P016-C2 VHL contains 29 MLPA probes with amplification products between 166 and 427 nucleotides (nt). This includes 9 probe(s) for the VHL gene (two or more probes for each exon), 6 probes for genes located close to VHL (FANCD2, BRK1/C3orf10/HSPC300, IRAK2 and GHRL), 2 probes on 3p which are further telomeric or centromeric from VHL, and 12 reference probes detecting sequences on other chromosomes. Complete probe sequences and the identity of the genes detected by the reference probes are available online (www.mlpa.com).

This probemix contains nine quality control fragments generating amplification products between 64 and 105 nt: four DNA Quantity fragments (Q-fragments), two DNA Denaturation fragments (D-fragments), one Benchmark fragment, and one chromosome X and one chromosome Y-specific fragment. More information on how to interpret observations on these control fragments can be found in the MLPA General Protocol and online at www.mlpa.com.