What are the other Names for this Condition? (Also known as/Synonyms)

• Autosomal Recessive PHA Type 1
• Generalized PHA1
• Generalized Pseudohypoaldosteronism Type 1

What is Autosomal Recessive Pseudohypoaldosteronism Type 1? (Definition/Background Information)

• Autosomal Recessive Pseudohypoaldosteronism Type 1 is a disorder of electrolyte metabolism characterized by excess loss of salt in the urine and high concentrations of sodium in sweat, stool, and saliva
• The disorder involves multiple organ systems and is especially dangerous in the newborn period. Respiratory tract infections are common in affected children
• Treatment involves aggressive salt replacement and control of hyperkalemia. The disorder may become less severe with age
• Autosomal Recessive Pseudohypoaldosteronism Type 1 is caused by mutations in the genes coding for the subunits of the amiloride-sensitive sodium channel (SCNN1A, SCNN1B and SCNN1G)

(Source: Autosomal Recessive Pseudohypoaldosteronism Type 1; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Autosomal Recessive Pseudohypoaldosteronism Type 1? (Age and Sex Distribution)

• Autosomal Recessive Pseudohypoaldosteronism Type 1 is a rare congenital disorder. The presentation of symptoms may occur at birth
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Autosomal Recessive Pseudohypoaldosteronism Type 1? (Predisposing Factors)

• A positive family history may be an important risk factor, since Autosomal Recessive Pseudohypoaldosteronism Type 1 can be inherited
• Children born to consanguineous parents bear an increased risk of developing the disorder

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Autosomal Recessive Pseudohypoaldosteronism Type 1? (Etiology)

• Autosomal Recessive Pseudohypoaldosteronism Type 1 is caused by mutations in the genes coding for the subunits of the amiloride-sensitive sodium channel (SCNN1A, SCNN1B and SCNN1G)
• The disorder is inherited in an autosomal recessive manner

(Source: Autosomal Recessive Pseudohypoaldosteronism Type 1; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Autosomal Recessive Pseudohypoaldosteronism Type 1?

The signs and symptoms of Autosomal Recessive Pseudohypoaldosteronism Type 1 may include:

• Dehydration
• Diarrhea
• Feeding difficulties in infancy
• Hyperactive renin-angiotensin system
• Hyperaldosteronism
• Hyperkalemia
• Hyponatremia
• Hypotension
• Metabolic acidosis
• Pseudohypoaldosteronism (PHA)
• Recurrent respiratory infections
• Renal salt-wasting
• Vomiting

(Source: Autosomal Recessive Pseudohypoaldosteronism Type 1; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Autosomal Recessive Pseudohypoaldosteronism Type 1 Diagnosed?

Autosomal Recessive Pseudohypoaldosteronism Type 1 is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Blood tests to check for the following:
• Hyponatremia (low sodium in blood)
• Hyperkalemia (low potassium in blood)
• Increased plasma renin activity 
• Elevated aldosterone levels
• Imaging studies of the affected region
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Autosomal Recessive Pseudohypoaldosteronism Type 1?

The complications of Autosomal Recessive Pseudohypoaldosteronism Type 1 may include:

• Insufficient weight gain due to feeding difficulties
• Damage to tissues and organs as a result of recurring infections in the respiratory tract
• Failure to thrive

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Autosomal Recessive Pseudohypoaldosteronism Type 1 Treated?

• There is no cure for Autosomal Recessive Pseudohypoaldosteronism Type 1, since it is a genetic condition
• The treatment is usually given to manage the signs and symptoms and any complication that develops
• Replacement of salt and potassium to counter hyponatremia and hypokalemia, respectively, may be necessary

How can Autosomal Recessive Pseudohypoaldosteronism Type 1 be Prevented?

Autosomal Recessive Pseudohypoaldosteronism Type 1 may not be preventable, since it is a genetic disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders
• Regular medical screening at periodic intervals with tests and physical examinations are recommended

What is the Prognosis of Autosomal Recessive Pseudohypoaldosteronism Type 1? (Outcomes/Resolutions)

• The prognosis of Autosomal Recessive Pseudohypoaldosteronism Type 1 is dependent upon the severity of the signs and symptoms and associated complications, if any
• A proper diagnosis and prompt treatment of the condition during the neonatal period is critical, as the disorder is severe and potentially life-threatening at this stage
• Affected individuals often require life-long supplementation of salt, although the severity and frequency of symptoms are reported to lessen with age

Additional and Relevant Useful Information for Autosomal Recessive Pseudohypoaldosteronism Type 1:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/