Novel Mutations in the SCNN1A Gene Causing
Pseudohypoaldosteronism Type 1
Jian Wang1,2., Tingting Yu1., Lei Yin3, Jing Li3, Li Yu2, Ye Shen3, Yongguo Yu1,3, Yongnian Shen3,
1Research Division of Birth Defects, Institute of Pediatric Translational Medicine, Shanghai Children’s Medical Center, Shanghai Jiaotong University School of Medicine,
Shanghai, P. R. China, 2Department of Laboratory Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America, 3Department of Pediatrics,
Shanghai Children’s Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, P. R. China
Pseudohypoaldosteronism type 1 (PHA1) is a rare inherited disease characterized by resistance to the actions of
aldosterone. Mutations in the subunit genes (SCNN1A, SCNN1B, SCNN1G) of the epithelial sodium channel (ENaC) and the
NR3C2 gene encoding the mineralocorticoid receptor, result in systemic PHA1 and renal PHA1 respectively. Common clinical
manifestations of PHA1 include salt wasting, hyperkalaemia, metabolic acidosis and elevated plasma aldosterone levels in
the neonatal period. In this study, we describe the clinical and biochemical manifestations in two Chinese patients with
systemic PHA1. Sequence analysis of the SCNN1A gene revealed a compound heterozygous mutation (c.1311delG and
c.1439+1G.C) in one patient and a homozygous mutation (c.814_815insG) in another patient, all three variants are novel.
Further analysis of the splicing pattern in a minigene construct showed that the c.1439+1G.C mutation can lead to the
retainment of intron 9 as the 59-donor splice site disappears during post-transcriptional processing of mRNA. In conclusion,
our study identified three novel SCNN1A gene mutations in two Chinese patients with systemic PHA1.
Citation: Wang J, Yu T, Yin L, Li J, Yu L, et al. (2013) Novel Mutations in the SCNN1A Gene Causing Pseudohypoaldosteronism Type 1. PLoS ONE 8(6): e65676.
Editor: Andreas R. Janecke, Innsbruck Medical University, Austria
Received November 22, 2012; Accepted April 27, 2013; Published June 6, 2013
Copyright: ? 2013 Wang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: The study was supported by the National Natural Science Foundation of China (Grant No. 81201353) and Research Fund of Health Bureau of Shanghai
Municipality (Grant No. 20114y072). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
* E-mail: firstname.lastname@example.org
. These authors contributed equally to this work.
Pseudohypoaldosteronism type 1 (PHA1) is a rare inherited
disease characterized by resistance to the actions of aldosterone. It
was first described in 1958 by Cheek and Perry , and common
clinical manifestations include salt wasting, hyperkalaemia, met-
abolic acidosis and elevated plasma aldosterone levels in the
neonatal period . According to the clinical manifestations and
Mendelian inheritance patterns, PHA1 can be classified as either
Renal PHA1 (autosomal dominant, OMIM177735) or the more
severe systemic PHA1 (autosomal recessive, OMIM264350) .
Renal PHA1 results from a defect in the tubular response to
aldosterone caused by inactivating mutations in the NR3C2 gene
(4q31) encoding the mineralocorticoid receptor . Systemic
PHA1 is caused by mutations in the genes encoding the subunits of
the epithelial sodium channel (ENaC): alpha subunit (SCNN1A;
12p13), beta subunit (SCNN1B; 16p12.2-p12.1), or gamma subunit
(SCNN1G; 16p12) . However, some special cases of PHA1 have
been reported. Hubert et al.  described a newborn with severe
recessive PHA1 caused by two heterozygous mutations in NR3C2.
Dirlewanger et al.  also reported that a homozygous missense
mutation in SCNN1A is responsible for a transient neonatal form of
In the 55 years since PHA was first known in the 1950s,
sufficient clinical descriptions have accumulated in the literatures.
Still, the symptoms of PHA1 are easily confused with that of other
endocrine disorders, especially if the pediatrician cannot get
specific biochemical findings . The symptoms of PHA1 are
easily confused with the symptoms of congenital adrenal hyper-
plasia (CAH) associated with 21-hydroxylase deficiency or 3-beta-
hydroxysteroid dehydrogenase deficiency; and the symptoms of
hypoaldosteronism (HA) due to aldosterone deficiency, antenatal
or infantile Bartter syndrome. In addition, respiratory tract
infections associated with PHA1 may be mistaken for symptoms
of cystic fibrosis . Such confusion delays diagnosis when prompt
treatment of PHA1 is essential, as death may occur as a result of
salt depletion and high blood potassium level .
In this study, two pediatric patients who suffer from PHA1 were
promptly diagnosed with molecular genetic tests and treated.
Using molecular genetic tests, we identified three novel mutations
in the SCNN1A gene. We further confirmed the pathogenicity of
the c.1439+1G.C mutation by analyzing its effect on splicing in a
Subjects and Methods
neonatal intensive care unit as a result of her refusal to be
breastfeed, poor response, weak cries and cold extremities.
Physical examination: Weight 3100 g (SDS=20.56), Height
49.5 cm (SDS=20.37), Heart rate 125/min, Respiratory rate
A 5-day-old female infant was admitted to the
PLOS ONE | www.plosone.org1 June 2013 | Volume 8 | Issue 6 | e65676
Conceived and designed the experiments: JW QF. Performed the
experiments: JW TY. Analyzed the data: JW L. Yu YY. Contributed
reagents/materials/analysis tools: JW L. Yu YY. Wrote the paper: JW QF.
Clinical diagnostic and therapy: L. Yin JL Ye Shen Yongnian Shen.
1. Cheek DB, Perry JW (1958) A salt wasting syndrome in infancy. Arch Dis Child
2. Riepe FG (2009) Clinical and molecular features of type 1 pseudohypoaldoster-
onism. Horm Res 72: 1–9.
3. Furgeson SB, Linas S (2010) Mechanisms of type I and type II pseudohypoal-
dosteronism. J Am Soc Nephrol 21: 1842–1845.
4. Hubert EL, Teissier R, Fernandes-Rosa FL, Fay M, Rafestin-Oblin ME, et al.
(2011) Mineralocorticoid receptor mutations and a severe recessive pseudohy-
poaldosteronism type 1. J Am Soc Nephrol 22: 1997–2003.
5. Dirlewanger M, Huser D, Zennaro MC, Girardin E, Schild L, et al. (2011) A
homozygous missense mutation in SCNN1A is responsible for a transient
neonatal form of pseudohypoaldosteronism type 1. Am J Physiol Endocrinol
Metab 301: E467–73.
6. Manikam L, Cornes MP, Kalra D, Ford C, Gama R (2011) Transient
pseudohypoaldosteronism masquerading as congenital adrenal hyperplasia. Ann
Clin Biochem 48: 380–382.
7. Schaedel C, Marthinsen L, Kristoffersson AC, Kornfa ¨lt R, Nilsson KO, et al.
(1999) Lung symptoms in pseudohypoaldosteronism type 1 are associated with
deficiency of the alpha-subunit of the epithelial sodium channel. J Pediatr 135:
8. Gu ¨ran T, Deg ˘irmenci S, Bulut I˙K, Say A, Riepe FG, et al. (2011) Critical points
in the management of pseudohypoaldosteronism type 1. J Clin Res Pediatr
Endocrinol 3: 98–100.
9. Schweiger B, Moriarty MW, Cadnapaphornchai MA (2009) Case report: severe
neonatal hyperkalemia due to pseudohypoaldosteronism type 1. Curr Opin
Pediatr 21: 269–271.
10. Choi MJ, Ziyadeh FN (2008) The utility of the transtubular potassium gradient
in the evaluation of hyperkalemia. J Am Soc Nephrol 19: 424–426.
11. Belot A, Ranchin B, Fichtner C, Pujo L, Rossier BC, et al. (2008)
Pseudohypoaldosteronisms, report on a 10-patient series. Nephrol Dial
Transplant 23: 1636–1641.
12. Chang SS, Grunder S, Hanukoglu A, Ro ¨sler A, Mathew PM, et al. (1996)
Mutations in subunits of the epithelial sodium channel cause salt wasting with
hyperkalaemic acidosis, pseudohypoaldosteronism type 1. Nat Genet 12: 248–
13. Kerem E, Bistritzer T, Hanukoglu A, Hofmann T, Zhou Z, et al. (1999)
Pulmonary epithelial sodium-channel dysfunction and excess airway liquid in
pseudohypoaldosteronism. N Engl J Med 341: 156–162.
14. Bonny O, Knoers N, Monnens L, Rossier BC (2002) A novel mutation of the
epithelial Na+ channel causes type 1 pseudohypoaldosteronism. Pediatr Nephrol
15. Edelheit O, Hanukoglu I, Gizewska M, Kandemir N, Tenenbaum-Rakover Y,
et al. (2005) Novel mutations in epithelial sodium channel (ENaC) subunit genes
and phenotypic expression of multisystem pseudohypoaldosteronism. Clin
Endocrinol (Oxf) 62: 547–553.
16. Huppmann S, Lankes E, Schnabel D, Bu ¨hrer C (2011) Unimpaired postnatal
respiratory adaptation in a preterm human infant with a homozygous ENaC-a
unit loss-of-function mutation. J Perinatol 31: 802–803.
17. Canessa CM, Schild L, Buell G, Thorens B, Gautschi I, et al. (1994) Amiloride-
sensitive epithelial Na+ channel is made of three homologous subunits. Nature
18. Garty H, Palmer LG (1997) Epithelial sodium channels: function, structure, and
regulation. Physiol Rev 77: 359–396.
Novel Mutations in SCNN1A Gene
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