title: Pseudohypoaldosteronism in a newborn male with functional polymorphisms in the mineralocorticoid receptor genes.
abstract: Hyponatremia and hyperkalemia in infancy can be attributed to various causes, originating from a variety of renal and genetic disorders. Pseudohypoaldosteronism type 1 (PHA1) is one of these disorders, causing mineralocorticoid resistance that results in urinary salt wasting, failure to thrive, metabolic acidosis, and dehydration. PHA1 is heterogeneous in etiology. Inactivating mutations in the NR3C2 gene (4q31.1), which encodes the mineralocorticoid receptor, causes a less severe autosomal dominant form that is restricted to the kidney, while mutations in the amiloride-sensitive epithelial sodium channel gene (alpha subunit=SCNN1A, 12p13; beta subunit=SCNN1b, 16p12.2-p12.1; gamma subunit=SCNN1G, 16p12) causes a more severe autosomal recessive form, which has systemic effects. Here we report a neonatal case of kidney restricted PHA1 (renal type of PHA1) who first showed laboratory abnormalities before obvious PHA1 manifestations, with two functional polymorphisms in the NR3C2 gene. This is the second genetically confirmed case in Korea and the first to show functional polymorphisms that have previously been reported in the literature.
authors.affiliation: Department of Pediatrics, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea.
authors.forename: Hyun Ah
authors.initials: HA
authors.lastname: Jeong
authors.affiliation: Department of Pediatrics, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea.
authors.forename: Yoon Kyoung
authors.initials: YK
authors.lastname: Park
authors.affiliation: Department of Pediatrics, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea.
authors.forename: Yeong Sang
authors.initials: YS
authors.lastname: Jung
authors.affiliation: Department of Laboratory Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Myung-Hyun
authors.initials: MH
authors.lastname: Nam
authors.affiliation: Korea University College of Medicine, Seoul, Korea.
authors.forename: Hyo-Kyoung
authors.initials: HK
authors.lastname: Nam
authors.affiliation: Korea University College of Medicine, Seoul, Korea.
authors.forename: Kee Hyoung
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea.
authors.forename: Young-Jun
authors.initials: YJ
authors.lastname: Rhie
keywords: Hyperkalemia; Hyponatremia; Mineralocorticoid receptors; NR3C2 gene; Pseudohypoaldosteronism
references.citation: J Am Soc Nephrol. 2006 May;17(5):1429-36
references.pmid: 16611713
references.citation: Hum Genet. 2003 Jan;112(1):91-7
references.pmid: 12483305
references.citation: Endocrinol Diabetes Metab Case Rep. 2013;2013:130010
references.pmid: 24616761
references.citation: Korean J Pediatr. 2011 Feb;54(2):90-3
references.pmid: 21503203
references.citation: Clin Endocrinol (Oxf). 2005 May;62(5):513-20
references.pmid: 15853818
references.citation: Hypertension. 2010 Nov;56(5):995-1002
references.pmid: 20855654
references.citation: Endocr Dev. 2013;24:86-95
references.pmid: 23392097
references.citation: Steroids. 1996 Apr;61(4):189-92
references.pmid: 8732998
references.citation: Nat Genet. 1996 Mar;12(3):248-53
references.pmid: 8589714
references.citation: Nat Genet. 1998 Jul;19(3):279-81
references.pmid: 9662404
references.citation: Arch Dis Child. 1958 Jun;33(169):252-6
references.pmid: 13545877