Syndromes of impaired ion handling in the distal nephron: pseudohypoaldosteronism and familial hyperkalemic hypertension

Pseudohypoaldosteronism type 1 secondary to vesicoureteral reflux: An endocrinologic emergency

“…As a result, vasoconstriction, decreased glomerular filtration rate, and natriuresis occur, related to transient damage to aldosterone receptors. 7 During the first months of life, because of tubule immaturity, high aldosterone levels are required for adequate maintenance of water and electrolyte balance, which could be affected by uropathy, with or without an added infectious process.…”

Pseudohypoaldosteronism Type 1

“…PHA1 includes two different forms with different severity of the disease and phenotype: a systemic type of disease with autosomal recessive inheritance (sPHA1 or AR-PHA1) and a renal form with autosomal dominant inheritance (rPHA1 or AD-PHA1). [20][21][22][23] In addition, there is a secondary form of PHA, may be called as PHA type 3 (PHA3), which is characterized by transient mineralocorticoid resistance associated with various kidney diseases, mostly urinary tract infections and obstructive uropathies ( Table 1).…”

“…22) Autosomal dominant pseudohypoaldosteronism type 1 AD-PHA1 (OMIM #177735) is characterized by an isolated renal resistance to aldosterone, leading to renal salt wasting, dehydration and failure to thrive during infancy. 1,[20][21][22][23][24][25] The main clinical symptom is insufficient weight gain due to chronic dehydration, and the cardinal laboratory abnormalities are hyponatremia, hyperkalemia, and metabolic acidosis despite elevated plasma renin activity and aldosterone levels. [20][21][22][23][24][25] AD-PHA1 is caused by inactivating mutations in the NR3C2 gene encoding MR, 26) and heterozygous mutations have been detected in approximately 75% of patients with this disease.…”

“…Exogenous mineralocorticoid treatment has no effect in patients with AD-PHA1, and patients usually respond well to sufficient enteral or parenteral salt supplementation. 1,22,23) Hyperkalemia is generally mild, and chronic ion exchange resin therapy to control hyperkalemia is rarely required. Interestingly, these abnormalities improve with increasing age in most cases, and the salt treatment becomes generally unnecessary by 2 to 3 years of age.…”

“…Interestingly, these abnormalities improve with increasing age in most cases, and the salt treatment becomes generally unnecessary by 2 to 3 years of age. 1,22,23,26,27) The reason for such spontaneous resolution of symptoms after infancy is not well understood, but it can be explained by (1) the change in diet from low-sodium human breast milk to higher salt diet, (2) maturation of Na + reabsorption function of the renal tubules with increasing age, (3) chronically upregulated renin-angiotensin-aldosterone system, and (4) replacement of distal sodium reabsorption by proximal parts of the tubules. 20,26,27) However, high plasma aldosterone levels may persist even after normalization of other laboratory findings in most cases.…”