VHL and neoplasm: It is located on chromosome 3p25-26 and consists of 3 exons that encode a 213 amino-acid protein (pVHL) with a molecular weight of  ̃24 to 30 kDa (VHL30).[16] A second pVHL isoform of 160 amino acids of approximately 19 kDa (VHL19) is produced as a result of internal translational initiation at an in-frame start codon (ATG) at codon 54.[17–20] Both isoforms apprear to retain tumor suppressor activity perhaps accounting for the paucity of pathogenic mutations affecting the first 50 amino acid residues.