You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Disease"].

Please return the output as a JSON object of the format: {"Disease" : ["COVID-19", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Expression of the von Hippel-Lindau disease tumour suppressor gene during human embryogenesis. The von Hippel-Lindau (VHL) disease product is thought to down-regulate transcription by antagonizing elongin-enhanced transcriptional elongation. Germline VHL gene mutations predispose to the development of retinal, cerebellar and spinal haemangioblastomas, renal cell carcinoma and phaeochromocytoma. In addition, somatic Inactivation of the VHL gene is frequent in sporadic renal cell carcinoma and haemangioblastoma. Regulation of transcript elongation is an important control mechanism for gene expression and the VHL gene might modify the expression of proto-oncogenes and growth suppressor genes during embryogenesis. We therefore investigated the expression of VHL mRNA during human embryogenesis by in situ hybridization studies at 4, 6 and 10 weeks post conception. Although VHL mRNA was expressed in all three germ layers, strong expression was noted in the central nervous system, kidneys, testis and lung. Within the kidney, VHL mRNA was differentially expressed within renal tubules suggesting that the VHL gene product may have a specific role in kidney development. Two alternatively spliced VHL mRNAs characterized by inclusion (isoform I) or exclusion (isoform II) of exon 2 are transcribed in adult tissues. To investigate if the two isoforms are differentially expressed during embryogenesis, VHL mRNA was reverse transcribed from 13 fetal tissues (8-10 weeks gestation). The quantitative distribution of VHL mRNA within fetal tissues reflected that seen by in situ hybridization and the ratio of the two VHL isoforms was similar between tissues. Although the genes regulated by the VHL gene product have not yet been identified, our findings are compatible with the hypothesis that VHL-mediated control of transcriptional elongation may have a role in normal human development..
{"Disease": ["retinal, cerebellar and spinal haemangioblastomas", "haemangioblastoma", "VHL", "von Hippel-Lindau (VHL) disease", "renal cell carcinoma", "phaeochromocytoma", "sporadic renal cell carcinoma", "von Hippel-Lindau disease tumour"]}