The exact prevalence of PFBC is unknown, but population-based genomic analysis indicates that it is underestimated and underdiagnosed,1 with a molecular diagnosis achieved in only up to 50% of PFBC cases.2 The pathogenesis of PFBC involves calcium and phosphate homeostasis via mutations in SLC20A2 (OMIM: 158378) and XPR1 (OMIM: 605237) and endothelial integrity and function affecting the blood-brain barrier via mutations in PDGFB (OMIM: 190040) and PDGFRB (OMIM: 173410). This evidence concerns the gene XPR1 and bilateral striopallidodentate calcinosis.