Pseudohypoaldosteronism type II: the relevance of a challenging diagnosis

Pseudohypoaldosteronism type II (PHA II) is a rare genetic syndrome caused by mutations in the WNK1, WNK4, KLHL3 and CUL3 genes, leading to hypertension, hyperkalaemia, and hyperchloremic metabolic acidosis. Each mutation confers a different phenotype, with a large spectrum of clinical presentations, which can delay the diagnosis. We report a case of a 31-year-old female with hypertension. She had uncharacteristic facies, average height and no family history of hypertension or hyperkalaemia. Laboratory data showed hyperkalaemia, hyperchloremic metabolic acidosis, hypercalciuria and suppressed renin. Genetic testing revealed a c.478G>T, p.(Asp160Tyr) variant in the KLHL3 gene, in apparent homozygosity. Based on clinical history, laboratory findings, and genetic testing, a diagnosis of PHA II was made. This is a representative case of a mild PHA II phenotype, with a non-previously reported KLHL3 mutation, highlighting the importance of a high level of suspicion for PHA II.