The genes SLC20A1 and SLC20A2 encode for phosphate transporters 1 and 2 (PiT1 and PiT2 respectively). They both have a broad tissue distribution and may play a general housekeeping role in phosphate transport such as absorbing phosphate from interstitial fluid and in extracellular matrix and cartilage calcification as well as in vascular calcification. They possess Na+-coupled phosphate (Pi) cotransporter function with a stoichiometry of 2:1 (Na+:Pi). Defects in SLC20A2 can cause idiopathic basal ganglia calcification 1 (IBGC1; MIM:213600), an autosomal dominant disorder characterised by vascular and pericapillary calcification by calcium phosphate in the basal ganglia and other brain regions. Affected individuals can either be asymptomatic or show a wide spectrum of neuropsychiatric symptoms including parkinsonism and dementia (Wang et al. 2012, Hsu et al. 2013, Ashtari et al. 2013, Forster et al. 2013).