An assessment of serum/urine potassium (K) and osmolality values, blood gas analysis results, plasma renin activity (PRA), and serum levels of aldosterone and cortisol are essential.
Question 2:
Clinical diagnosis of pseudohypoaldosteronism type 1 (PHA-1) was made on the basis of true volume depletion, hyponatremia, hyperkalemia, hyperreninemic hyperaldosteronism, and normal cortisol level. Molecular genetic analysis of NR3C2 for PHA-1A and the subunit genes (SCNN1A, SCNN1B, SCNN1G) of the amiloride-sensitive epithelial sodium channel (ENaC) for PHA-1B revealed a novel heterozygous mutation in NR3C2, c.2540_2546delAACTATG, in exon 6, resulting in a frameshift p.Glu847Alafs*23 in our patient and her father (Fig. 1).
Fig. 1
Pedigree of the patient and her family. Square Male, circles females, filled symbols affected individuals. Arrow indicates a heterozygous deletion mutation in exon 6 of the NR3C2 gene (c.2540_2546delAACTATG, p.Glu847Alafs*23)
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Question 3:
Sodium chloride (NaCl) and bicarbonate (HCO3) supplements and K-binding resins were the mainstay of treatment to normalize the electrolyte imbalance and prevent a life-threatening event.
