Hypertension Accompanied by Hyperaldosteronism, Hyperkalemia, and Hyperchloremic Acidosis: A Case Report and Literature Review

Aldosterone defects in infants and young children with hyperkalemia: A single center retrospective study

INTRODUCTION

Hyperkalemia is a rare but severe condition in young children and usually discovered as a result of hemolysis of the blood samples taken. However, patients with defects in either aldosterone biosynthesis or function can also present with hyperkalemia- as well hyponatremia-associated, and metabolic acidosis. It is a challenge to make an accurate diagnosis of these clinical conditions. We conducted this study to investigate the clinical and genetic features of aldosterone signaling defects associated hyperkalemia in young children.

METHOD

A retrospective review was conducted at the pediatric department of the First Affiliated Hospital of Guangxi Medical University from 2012 to 2022.

RESULTS

47 patients with hyperkalemia were enrolled, of which 80.9% (n = 38) were diagnosed with primary hypoaldosteronism, including congenital adrenal hyperplasia due to 21-hydroxylase deficiency (n = 32), isolated hypoaldosteronism (n = 1) due to CYP11B2 gene mutation and Xp21 contiguous gene deletion syndrome (n = 1). Additionally, 4 patients were clinically-diagnosed with primary adrenal insufficiency. Nine patients were confirmed with aldosterone resistance, of which one child was diagnosed with pseudohypoaldosteronism (PHA) type 1 with a mutation in the NR3C2 gene and 3 children were identified with PHA type 2 due to novel mutations in either the CUL3 or KLHL3 genes. Five patients had PHA type 3 because of pathologies of either the urinary or intestinal tracts.

CONCLUSIONS

The etiologies of infants with hyperkalemia associated with aldosterone defects were mostly due to primary hypoaldosteronism. An elevated plasma aldosterone level may be a useful biomarker for the diagnosis an aldosterone functional defect in patients presented with hyperkalemia. However, a normal plasma aldosterone level does rule out an aldosterone defect in either its biosynthesis or function, especially in young infants. Molecular genetic analyses can greatly help to clarify the complexity of disorders and can be used to confirm the diagnosis.

[A Case of Pseudohypoaldosteronism Type Ⅱ (PHA2) Caused by a Novel Mutation of KLHL3]

The patient, a 41-year-old woman, was admitted because "it was found out she had elevated serum potassium levels for 18 days". Eighteen days prior to admission at our hospital, the patient was found to have elevated serum potassium during hospitalization at another hospital, where the patient received symptomatic treatment and was discharged after her serum potassium returned to a normal level. However, the patient still had elevated serum potassium repeatedly and was referred to our hospital for further examination. The patient had a history of acute nephritis and gestational hypertension. Six months prior to admission at our hospital, it was found out that the patient had slightly elevated blood pressure, but no intervention was done. The patient's father has a history of hypertension and diabetes. After admission, laboratory results showed that the patient had hyperkalemia, hyperchloremia and metabolic acidosis. The level of plasma renin was obviously below the normal range, but the concentration of plasma aldosterone was within the normal range. A new mutation locus (c.1115delG) in KLHL3 (Kelch like family member 3) gene was revealed by genetic testing, leading to the diagnosis of pseudoaldosteronism type Ⅱ (PHA2). The patient was given regular treatment of oral hydrochlorothiazide hydrochloride at set intervals. Subsequently, her blood electrolyte level, blood pH, BE and BEB have returned to normal levels. The patient was followed up for 12 months and did not feel unwell during the follow-up period.

A case report of pseudohypoaldosteronism type II with a homozygous KLHL3 variant accompanied by hyperthyroidism

BACKGROUND

Pseudohypoaldosteronism type II (PHAII), also called Gordon syndrome, is a rare hereditary disease caused by variants in the WNK1, WNK4, KLHL3 and CUL3 genes. The combination of PHAII with hyperthyroidism and secondary hyperparathyroidism has not been reported previously.

CASE PRESENTATION

A 54-year-old female with recently diagnosed Graves' disease presented hyperkalemia, hypertension, hypercalciuria, elevated levels of parathyroid hormone (PTH) and normal renal function. PHAII was established based on the finding of a homozygous variant (c.328 A > G, T110A) in the KLHL3 gene. Low-dose thiazide diuretics normalized her potassium, calcium and PTH.

CONCLUSIONS

PHAII caused by a KLHL3 variant can affect adults later in life. This diagnosis should be considered in patients with hypertension, consistent hyperkalemia, and normal eGFR and can be corrected by thiazides. The patient also had hyperthyroidism and secondary hyperparathyroidism. The latter was also corrected by thiazide treatment. The hyperthyroidism was assumed to be unrelated to PHAII.