PTH and familial primary hypomagnesemia: The complete genetic study revealed one likely pathogenic variant (p.(Ser795*)) in one patient with elevated serum Ca2+ and PTH levels, hypocalciuria and hypomagnesemia; and 3 variants not previously reported of uncertain significance in other three patients diagnosed of Bartter syndrome (p.(Ser186Thr) and p.(Ile260Phe)) and calcium metabolism disorder (p.(Asp335Asn)).