In the families described here, we used a combination of homozygosity mapping, exome sequencing (ES), functional studies, and mouse model to identify and characterize the causal variants in JAM2 (MIM: 606870) encoding for the junctional-adhesion-molecule-2, a tight-junction protein as a cause of PFBC. The gene discussed is JAM2; the disease is bilateral striopallidodentate calcinosis.