CLDN16 and familial primary hypomagnesemia with hypercalciuria and nephrocalcinosis: Pathogenic variants in CLDN16 and CLDN19 genes cause a rare autosomal recessive disease named Familial Hypomagnesaemia with Hypercalciuria and Nephrocalcinosis (FHHNC; MIM #248250 and #248190) [1–3].