Identification of a VHL germline deletion in a family with Von Hippel-Lindau syndrome using MLPA-NGS.

Von Hippel-Lindau syndrome (VHL) is an autosomal dominant disorder characterized by the development of tumors and cysts in multiple organs. Pathogenic variants in VHL are known to be associated with the development of this syndrome. Therefore, the present study aimed to investigate VHL rearrangements in a family with VHL syndrome. In the proband, who presented with retinal hemangioma, whole exome sequencing (WES) revealed significant genetic variation. However, WES did not detect germline deletion in VHL in the proband's son. Furthermore, multiplex ligation-dependent probe amplification (MLPA)-next-generation sequencing (NGS) analysis showed that the genomes of the proband and her son encompassed a deletion in VHL, extending from exon 2 to exon 3. Via increasing the probe density to gradually approach the breakpoint and following Sanger sequencing analysis, it was verified that an intermediate fragment of 6,662 bp was lost, with a reconnection occurring between chromosome 3:10145434 and 10,152,097 (GRCh38/hg38). Overall, the present study demonstrated that the application of MLPA-NGS technology combined with Sanger sequencing could be employed to precisely locate deleted DNA ‌fragments.