NSHPT (OMIM #239200) is a potentially life-threatening disorder most often caused by homozygous or compound heterozygous loss-of-function CaSR mutations (Table 1) (Chattopadhyay & Brown 2006, Hannan et al. 2012, Hannan & Thakker 2013). Here, CASR is linked to neonatal severe primary hyperparathyroidism.