Recently, Lenglet et al., 2018 identified a new VHL cryptic exon termed E1' deep in intron 1 that is naturally expressed in many tissues, and found E1' mutations in eight families with either erythrocytosis or VHL disease. The goal of this study was to determine the prevalence of E1' germline mutations from two cohorts, 221 patients with a single or multiple tumours, suggestive of VHL disease, and 946 patients with a Pheochromocytoma/paraganglioma (PPGL) but without an identified mutation in the three VHL exons or in the main PPGL susceptibility genes. They identified a rare germline genetic variant (maf <1%) in the E1’ VHL cryptic exon in 1% of patients (12/1167). Patient 1 was diagnosed at the age of 47 with follow up of a 5 year duration due to a Carotid body paraganglioma (PGL) and was found to have a germline c.340+563C>T E1' variant. Tumor analysis was performed for patient 1 since there was a paraffin embedded sample. Patient 1 did not have loss of heterozygosity, but the mutated allele was lost in the tumor. Immunostaining was negative for detection of CA9 expression. CA9 is a protein reported to influence regulation cell proliferation and tumor progression and is known to be expressed at the membrane of tumour cells in the case of VHL inactivation.