Pseudohypoaldosteronism Type 1 Newborn Patient with a Novel Mutation in SCNN1B

Abstract

Pseudohypoaldosteronism is a rare disease characterized by resistance to aldosterone-targeted organs, hyponatremia, hyperkalemia, metabolic acidosis, and severe salt loss in hyperaldosteronism. Homozygous mutations in SCNN1A, SCNN1B, and SCNN1G genes were found to be responsible for the etiology. About 80 cases with molecular basis have been reported to date. In this case, a newborn patient admitted to our neonatal intensive care unit due to feeding problems was examined. The parents of the patient had a consanguineous marriage, and they had lost their three sons due to hyperkalemia. Since she had hyponatremia and hyperkalemia, congenital adrenal hyperplasia was primarily considered. Although the initial evaluation was made in this direction, the patient was diagnosed as pseudohypoaldosteronism type 1 with the findings obtained during the process such as dehydration, cortisol levels, adrenocorticotropic hormone levels, and negative CYP21A2 analysis result. This clinical diagnosis was confirmed by the novel homozygous frame-shift variant c.1245_1246insC (p.N416Qfs*35) in SCNN1B shown by gene analysis. In this report, we seek to emphasize that aldosterone deficiency should be one of the first diagnoses to be considered in neonatal patients with hyponatremia, hyperkalemia, metabolic acidosis, and dehydration.

Keywords

pseudohypoaldosteronism - hyperkalemia - SCNN1B

• References

• 1 Belot A, Ranchin B, Fichtner C. , et al. Pseudohypoaldosteronisms, report on a 10-patient series. Nephrol Dial Transplant 2008; 23 (05) 1636-1641
• 2 Tetti M, Monticone S, Burrello J. , et al. Liddle syndrome: review of the literature and description of a new case. Int J Mol Sci 2018; 19 (03) 812
• 3 Amin N, Alvi NS, Barth JH. , et al. Pseudohypoaldosteronism type 1: clinical features and management in infancy. Endocrinol Diabetes Metab Case Rep 2013; 2013: 130010
• 4 Kurtoğlu S, Hatipoğlu N, Büyükayhan D. Neonatal tuz kaybı tablosu. Türkiye Klinikleri Journal of Pediatric Sci. 2008; 4: 90-105
• 5 Arai K, Chrousos GP. Syndromes of glucocorticoid and mineralocorticoid resistance. Steroids 1995; 60 (01) 173-179
• 6 Zennaro MC, Lombès M. Mineralocorticoid resistance. Trends Endocrinol Metab 2004; 15 (06) 264-270
• 7 Mendes C, Vaz Matos I, Ribeiro L, Oliveira MJ, Cardoso H, Borges T. [Congenital adrenal hyperplasia due to 21-hydroxylase deficiency: genotype-phenotype correlation]. Acta Med Port 2015; 28 (01) 56-62
• 8 Ağladıoğlu SY, Aycan Z, Kendirci HN, Erkek N, Baş VN. Does pseudohypoaldosteronism mask the diagnosis of congenital adrenal hyperplasia?. J Clin Res Pediatr Endocrinol 2011; 3 (04) 219-221
• 9 Gormley K, Dong Y, Sagnella GA. Regulation of the epithelial sodium channel by accessory proteins. Biochem J 2003; 371 (Pt 1): 1-14
• 10 Arai K, Chrousos GP. Aldosterone deficiency and resistance. In: De Groot LJ, Chrousos G, Dungan K. , et al., eds. South Dartmouth, MA: MDText.com, Inc.; 2016