Tacrolimus‐induced hypomagnesemia and hypercalciuria requires FKBP12 suggesting a role for calcineurin

Renal hypomagnesemia, hypercalciuria, nephrocalcinosis

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis in 2 sisters.

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) is a rare autosomal recessive tubular disorder characterized by excessive renal magnesium and calcium wasting, eventually, progressing to renal failure. It has been recently attributed to a mutation in the Claudin 16 (CLDN 16) gene of the Paracellin-1 (PCLN-1) tight junction protein. Herein, we report 2 sisters with FHHNC....

Nephrocalcinosis in siblings--familial hypomagnesemia, hypercalciuria with nephrocalcinosis (FHHNC syndrome).

Familial Hypomagnesemia, Hypercalciuria with Nephrocalcinosis is a rare autosomal recessive inherited disease associated with renal failure. Two girls born of consanguineous parentage aged 16 and 17 presented to us with renal failure, nephrocalcinosis and bone deformities. On evaluation they were found to have hypomagnesemia, hypercalciuria, increased fractional excretion of magnesium, hypocitr...

Charged surface residues of FKBP12 participate in formation of the FKBP12-FK506-calcineurin complex.

The mechanism of FK506 immunosuppression has been proposed to proceed by formation of a tight-binding complex with the intracellular 12-kDa FK506-binding protein (FKBP12). The FK506-FKBP12 complex then acts as a specific high-affinity inhibitor of the intracellular protein phosphatase PP2B (calcineurin), interrupting downstream dephosphorylation events required for T-cell activation. Site-direc...

Hypomagnesemia-hypercalciuria-nephrocalcinosis and ocular findings: a new claudin-19 mutation.

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) is an autosomal recessive syndrome that affects the tight junction proteins claudin-16 and claudin-19 in the thick ascending limb. In patients with claudin-19 mutations, additional symptoms such as visual impairment and other ophthalmologic findings are expected. In this report, we present a seven-year-old girl with polyur...