CLDN16 and renal hypomagnesemia 3: Renal hypomagnesemia 3 (OMIM phenotype number 248250) is an AR condition due to inactivating variants in CLDN16, resulting reduced reabsorption of calcium (hypercalciuria)and magnesium (hypermagnesuria) with hypomagnesemia, NC, NL, and progressive CKD (Godron et al., 2012).