Novel mutations in the SCNN1A gene causing Pseudohypoaldosteronism type 1

PLoS One. 2013 Jun 6;8(6):e65676. doi: 10.1371/journal.pone.0065676. Print 2013.

Abstract

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 5'-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.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing*
  • Asian Continental Ancestry Group
  • Base Sequence
  • Epithelial Sodium Channels / genetics*
  • Female
  • HEK293 Cells
  • Heterozygote
  • Homozygote
  • Humans
  • Infant
  • Infant, Newborn
  • Molecular Sequence Data
  • Mutation*
  • Pedigree
  • Pseudohypoaldosteronism / ethnology
  • Pseudohypoaldosteronism / genetics*
  • RNA Splice Sites

Substances

  • Epithelial Sodium Channels
  • RNA Splice Sites
  • SCNN1A protein, human

Grant support

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.