Clinical analysis of salt-wasting in infants due to genetic aetiology.

Abstract

Introduction: This study was aimed to get an overview of the clinical analyses and genetic characteristics of salt-wasting (SW) in infants caused by genetic aetiology.

Material and methods: A retrospective study was conducted for infants at the Paediatric Unit of the First Affiliated Hospital of Guangxi Medical University from January 2012 to July 2022.

Results: Thirty infants were enrolled in this retrospective study. Twenty-six infants (86.7%) were diagnosed with congenital adrenal hyperplasia (CAH), and all of them had SW type 21-hydroxylase deficiency. Four infants (13.3%) were non-CAH. One girl was diagnosed with congenital chloride diarrhoea due to known homozygous mutations in the SLC26A3 gene, and another girl had Barter's syndrome due to a mutation in the CLCNKB gene. One boy was diagnosed with pseudohypoaldosteronism type 1 due to a novel mutation in the NR3C2 gene, and another boy was confirmed with aldosterone synthase deficiency due to novel compound heterozygous mutations in the CYP11B2gene. Meanwhile, we verified the pathogenicity of the novel compound heterozygous of CYP11B2 gene in in vitro experiments.

Conclusions: The genetic aetiologies of infants with SW were mostly CAH. However, pseudohypoaldosteronism and aldosterone synthase deficiency should also be considered in infants who present with salt-wasting syndrome. Normal or high aldosterone levels cannot be a factor by which to rule out the possibility of aldosterone synthase deficiency (ASD) in infancy. Gene analysis can be used to confirm the disorder.