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Pseudohypoaldosteronism Type I


L. Aimee Hechanova

, MD, Texas Tech University Health Sciences Center, El Paso

Reviewed/Revised May 2022 | Modified Sep 2022

Pseudohypoaldosteronism type I is a group of rare hereditary disorders that cause the kidneys to retain too much potassium but excrete too much sodium and water, leading to hypotension. Symptoms may result from hypotension, hypovolemia, hyponatremia, and hyperkalemia. Treatment is with a high-sodium diet and sometimes fludrocortisone.

There are 3 types of pseudohypoaldosteronism:

  • Autosomal recessive pseudohypoaldosteronism type I

  • Autosomal dominant pseudohypoaldosteronism type I

  • Pseudohypoaldosteronism type II

Inheritance is autosomal recessive or autosomal dominant.

Pseudohypoaldosteronism type I resembles other forms of hypoaldosteronism except that aldosterone levels are high.

The very rare pseudohypoaldosteronism type II is not discussed here.

Autosomal recessive pseudohypoaldosteronism type I

The autosomal recessive form tends to be severe and permanent. Infants are resistant to the effects of aldosterone due to mutations causing decreased activity of the epithelial sodium channels (ENaC) located on the luminal membrane of the collecting tubule (overactivity of ENaC causes potassium excretion and sodium retention—see Liddle Syndrome Liddle Syndrome Liddle syndrome is a rare hereditary disorder involving increased activity of the epithelial sodium channel (ENaC), which causes the kidneys to excrete potassium but retain too much sodium and... read more ). The sodium channel in tissues other than the kidneys may be affected, leading to a miliary rash and/or complications similar to those of cystic fibrosis Cystic Fibrosis Cystic fibrosis is an inherited disease of the exocrine glands affecting primarily the gastrointestinal and respiratory systems. It leads to chronic lung disease, exocrine pancreatic insufficiency... read more Cystic Fibrosis .

Autosomal dominant pseudohypoaldosteronism type 1

Children are resistant to mineralocorticoids due to mutations of the mineralocorticoid receptor. The autosomal dominant form is usually less severe, affecting mainly the mineralocorticoid receptor in the kidney, and may resolve somewhat as children age.

Diagnosis of Pseudohypoaldosteronism Type I

  • Plasma renin and aldosterone levels

The diagnosis is suspected based on clinical findings of hypovolemia, high serum potassium, low serum sodium, high renin and aldosterone levels, particularly in infants with a positive family history. The diagnosis is confirmed by genetic testing.

Treatment of Pseudohypoaldosteronism Type I

  • High-sodium diet and sometimes fludrocortisone

A high-sodium diet helps maintain volume and BP and increases excretion of potassium. If diet is ineffective, fludrocortisone 0.5 to 1.0 mg orally twice/day or 1 to 2 mg orally once/day can be given.

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