Endocrine Journal
Online ISSN : 1348-4540
Print ISSN : 0918-8959
ISSN-L : 0918-8959
ORIGINAL
Classification of pseudohypoaldosteronism type II as type IV renal tubular acidosis: results of a literature review
Masanori Adachi Sakura MotegiKeiko NagaharaAyako OchiJunya ToyodaKatsumi Mizuno
Author information
JOURNAL FREE ACCESS FULL-TEXT HTML
Supplementary material

2023 Volume 70 Issue 7 Pages 723-729

Details
Abstract

Pseudohypoaldosteronism (PHA) type II (PHA2) is a genetic disorder that leads to volume overload and hyperkalemic metabolic acidosis. PHA2 and PHA type I (PHA1) have been considered to be genetic and pediatric counterparts to type IV renal tubular acidosis (RTA). Type IV RTA is frequently found in adults with chronic kidney disease and is characterized by hyperchloremic hyperkalemic acidosis with normal anion gap (AG). However, we recently observed that PHA1 was not always identical to type IV RTA. In this study, we focused on the acid-base balance in PHA2. Through a literature search published between 2008–2020, 46 molecularly diagnosed cases with PHA2 were identified (median age of 14 years). They comprised 11 sets of familial and 16 sporadic cases and the pathology was associated with mutations in WNK 4 (n = 1), KLHL3 (n = 17), and CUL3 (n = 9). The mean potassium (K+) level was 6.2 ± 0.9 mEq/L (n = 46, range 4.0–8.6 mEq/L), whereas that of chloride (Cl) was 110 ± 3.5 mEq/L (n = 41, 100–119 mEq/L), with 28 of 41 cases identified as hyperchloremic. More than half of the cases (18/35) presented with metabolic acidosis. Although AG data was obtained only in 16 cases, all but one cases were within normal AG range. Both Cl and HCO3 levels showed significant correlations with K+ levels, which suggested that the degree of hyperchloremia and acidosis reflect the clinical severity, and is closely related to the fundamental pathophysiology of PHA2. In conclusion, our study confirmed that PHA2 is compatible with type IV RTA based on laboratory findings.

Content from these authors
© The Japan Endocrine Society
Previous article Next article
feedback
Top