PTEN Hamartoma Tumor Syndrome (PHTS) is a hereditary syndrome defined by a pathogenic variant in the PTEN tumor suppressor gene. PHTS is rare and associated with an increased risk of different cancers, benign tumors, and neurological manifestations. Collaborating across all departments of clinical genetics in Denmark, we identified patients with PHTS and gathered information in order to calculate prevalence of clinical data, as well as to reclassify variants according to new evidence. We reclassified about a third of our PTEN variants, highlighting the clinical value of ongoing reclassification using PTEN to refine diagnosis, surveillance, and counselling. (https://jmg.bmj.com/content/early/2026/09/09/jmg-2026-111772)