Identification of Three Novel MAGED2 Variants Causing Antenatal Bartter Syndrome in Three Chinese Families

MAGED2 (3 novel variants, X-linked, hemizygous)

MAGED2 LOF variants → defective fetal renal NaCl tubular transport (inhibition of NKCC2 and NCC) → polyhydramnios + transient postnatal salt loss; spontaneous resolution at birth linked to postnatal activation of compensatory pathways

Report of three novel MAGED2 variants in three unrelated Chinese families presenting with transient antenatal Bartter syndrome (TABS). MAGED2, an X-linked gene encoded at Xp11, inhibits fetal renal NaCl cotransporters NKCC2 and NCC. All 3 families present with revealing antenatal polyhydramnios, with spontaneous resolution after birth. The article consolidates and expands the clinical and molecular spectrum of MAGED2-TABS, a significantly underdiagnosed condition in polyhydramnios of unknown etiology.

Synthesis written by Geno'X. For the full original abstract, please refer to the source publication.

MAGED2 should be systematically investigated in unexplained polyhydramnios in male fetuses, especially in populations at risk of consanguinity. The transient nature of Bartter after birth should not falsely reassure: antenatal hyperaldosteronism exposes to perinatal complications.

3 novel variants + 3 independent families (variant_recurrent) +2; complete pre-postnatal characterization +2; underrecognized X-linked gene +2; Genes +1