OBJECTIVE: Bartter syndrome is a severe inherited tubulopathy characterized by postnatal salt wasting, severe polyuria, dehydration, failure to thrive and secondary hyperaldosteronism. Prenatally, the disease is usually discovered following the onset of severe polyhydramnios in the second trimester. We studied amniotic fluid aldosterone concentration in Bartter syndrome and in controls. METHODS: Amniotic fluid aldosterone was assayed by radioimmunoassay. We undertook a retrospective case-control study based on 36 cases of prenatally suspected and postnatally confirmed Bartter syndrome (22 with identified mutations): and 72 gestational age matched controls presenting with polyhydramnios and 72 without polyhydramnios. Amniotic fluid aldosterone was compared between the three groups. RESULTS: The median amniotic fluid aldosterone concentration in the Bartter syndrome group (90 pg/mL) was not different from that in the controls with polyhydramnios (90 pg/mL, P = 0.33) or without polyhydramnios (87 pg/mL, P = 0.41). CONCLUSION: Amniotic fluid aldosterone assay cannot be used for prenatal diagnosis of Bartter syndrome.
OBJECTIVE:Bartter syndrome is a severe inherited tubulopathy characterized by postnatal salt wasting, severe polyuria, dehydration, failure to thrive and secondary hyperaldosteronism. Prenatally, the disease is usually discovered following the onset of severe polyhydramnios in the second trimester. We studied amniotic fluid aldosterone concentration in Bartter syndrome and in controls. METHODS: Amniotic fluid aldosterone was assayed by radioimmunoassay. We undertook a retrospective case-control study based on 36 cases of prenatally suspected and postnatally confirmed Bartter syndrome (22 with identified mutations): and 72 gestational age matched controls presenting with polyhydramnios and 72 without polyhydramnios. Amniotic fluid aldosterone was compared between the three groups. RESULTS: The median amniotic fluid aldosterone concentration in the Bartter syndrome group (90 pg/mL) was not different from that in the controls with polyhydramnios (90 pg/mL, P = 0.33) or without polyhydramnios (87 pg/mL, P = 0.41). CONCLUSION: Amniotic fluid aldosterone assay cannot be used for prenatal diagnosis of Bartter syndrome.