We present a case of PHA type I identified using whole-exome sequencing, with two novel frameshift mutations in the SCNN1B gene, which resulted in severe hyperkalaemia, hyponatraemia, metabolic acidosis, moreover, the emergence of compound heterozygotes of this mutant type may lead to growth retardation and early neonatal mortality. This evidence concerns the gene SCNN1B and Hyponatremia.