title: Polyuric-polydipsic syndrome in a pediatric case of non-glucocorticoid remediable familial hyperaldosteronism.
abstract: Familial hyperaldosteronism (FH) encompasses 3 types of autosomal dominant hyperaldosteronisms leading to inheritable hypertension. FH type II (FH-II), undistinguishable from sporadic hyperaldosteronism, represents the most frequent cause of inheritable hypertension and is believed to only manifest in adults. FH-III is a severe variety of PA resistant to pharmacotherapy and recently demonstrated to be caused by mutations in the gene encoding the potassium channel KCNJ5. In this report, we describe a FH pediatric patient, remarkable both for age at onset and unusual presentation: a two-years old girl with polyuric-polydipsic syndrome and severe hypertension, successfully treated with canrenone and amiloride. The girl had severe hypertension, hypokalemia, hypercalciuria, suppressed renin activity, high aldosterone, and unremarkable adrenal imaging. FH type I was ruled out by glucocorticoid suppression test, PCR test for CYP11B1/CYP11B2 gene, and urinary 18-oxo-cortisol and 18-hydroxy-cortisol excretion, which was in FH-II range. In spite of a clear-cut FH-II phenotype, the girl and her mother were found to harbor a FH-III genotype with KCNJ5 mutation (c.452G>A). Treatment with canrenone was started, resulting in prompt normalization of electrolytes and remission of polyuric-polydypsic syndrome. The addition of amiloride led to a complete normalization of blood pressure. This report expands the phenotypic spectrum of FH-III to a milder end, mimiking FH-II phenotype demonstrating that pharmacotherapy may be effective. This also implies that FH-II/III should be considered in the differential diagnosis of hypertensive children and, perhaps, that the offspring of patients with hyperaldosteronism should be screened for hypertension.
authors.affiliation: Department of Pediatrics, Division of Pediatric Endocrinology and Diabetology, University of Torino, Italy. mussa_alessandro@yahoo.it
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mussa
authors.forename: Roberta
authors.initials: R
authors.lastname: Camilla
authors.forename: Silvia
authors.initials: S
authors.lastname: Monticone
authors.forename: Francesco
authors.initials: F
authors.lastname: Porta
authors.forename: Daniele
authors.initials: D
authors.lastname: Tessaris
authors.forename: Francesca
authors.initials: F
authors.lastname: Verna
authors.forename: Paolo
authors.initials: P
authors.lastname: Mulatero
authors.forename: Silvia
authors.initials: S
authors.lastname: Einaudi
mesh_terms: D017668:Age of Onset; D002192:Canrenone / Q000627:therapeutic use; D002675:Child, Preschool; D005260:Female; D051676:G Protein-Coupled Inwardly-Rectifying Potassium Channels / Q000235:genetics; D005838:Genotype; D006801:Humans; D006929:Hyperaldosteronism / Q000150:complications* / Q000188:drug therapy / Q000235:genetics; D006973:Hypertension / Q000188:drug therapy / Q000209:etiology / Q000235:genetics; D000451:Mineralocorticoid Receptor Antagonists / Q000627:therapeutic use; D009154:Mutation; D010641:Phenotype; D059606:Polydipsia / Q000188:drug therapy / Q000209:etiology* / Q000235:genetics; D011141:Polyuria / Q000188:drug therapy / Q000209:etiology* / Q000235:genetics; D013577:Syndrome
chemical_list: D051676:G Protein-Coupled Inwardly-Rectifying Potassium Channels; C484274:KCNJ5 protein, human; D000451:Mineralocorticoid Receptor Antagonists; D002192:Canrenone