Hypomagnesemia is a significant clinical indicator in HNF1B mutation-related conditions.<h4>Conclusion</h4>Hyperuricemia, hypomagnesemia, and multiple renal cysts can manifest as renal symptoms of the microdeletion in the 17q12 region, with the spectrum of extra-renal manifestations continually expanding. Here, HNF1B is linked to familial primary hypomagnesemia.