title: Bartter syndrome prenatal diagnosis based on amniotic fluid biochemical analysis.
abstract: Bartter syndrome is an autosomic recessive disease characterized by severe polyuria and sodium renal loss. The responsible genes encode proteins involved in electrolyte tubular reabsorption. Prenatal manifestations, mainly recurrent polyhydramnios because of fetal polyuria, lead to premature delivery. After birth, polyuria leads to life-threatening dehydration. Prenatal genetic diagnosis needs an index case. The aim of this study was to analyze amniotic fluid biochemistry for the prediction of Bartter syndrome. We retrospectively studied 16 amniotic fluids of Bartter syndrome-affected fetuses diagnosed after birth, only six of them being genetically proven. We assayed total proteins, alpha-fetoprotein, and electrolytes and defined a Bartter index corresponding to the multiplication of total protein and of alpha-fetoprotein. Results were compared with two control groups matched for gestational age-non-Bartter polyhydramnios (n = 30) and nonpolyhydramnios (n = 60). In Bartter syndrome, we observed significant differences (p < 0.0001) for protein amniotic fluid levels when compared with the two control groups (1.55 g/L, 3.9 g/L, and 5.2 g/L, respectively) and low Bartter index (0.16, 0.82, and 1.0, respectively). No statistical difference was observed for electrolytes. In conclusion, Bartter syndrome can be prenatally suspected on amniotic fluid biochemistry (sensitivity 93% and specificity 100%), allowing appropriate management before and after birth.
authors.affiliation: Nephrologie Pediatrique, Hôpital Robert Debré AP-HP, Paris, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Garnier
authors.forename: Sophie
authors.initials: S
authors.lastname: Dreux
authors.forename: Rosa
authors.initials: R
authors.lastname: Vargas-Poussou
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Oury
authors.forename: Alexandra
authors.initials: A
authors.lastname: Benachi
authors.forename: Georges
authors.initials: G
authors.lastname: Deschênes
authors.forename: Françoise
authors.initials: F
authors.lastname: Muller
mesh_terms: D000653:Amniotic Fluid / Q000737:chemistry*; D001477:Bartter Syndrome / Q000175:diagnosis* / Q000235:genetics; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D042241:Early Diagnosis; D004573:Electrolytes / Q000032:analysis; D005260:Female; D005326:Fetal Proteins / Q000032:analysis*; D020022:Genetic Predisposition to Disease; D005865:Gestational Age; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D000509:alpha-Fetoproteins / Q000032:analysis
chemical_list: C097353:AFP protein, human; D015415:Biomarkers; D004573:Electrolytes; D005326:Fetal Proteins; D000509:alpha-Fetoproteins