Familial hyperaldosteronism type 1

Familial hyperaldosteronism type 1
[[File:|250px|]]
Synonyms	Glucocorticoid-remediable aldosteronism (GRA)
Pronounce	N/A
Specialty	N/A
Symptoms	Hypertension, hypokalemia, muscle weakness
Complications	Cardiovascular disease, stroke
Onset	Childhood or early adulthood
Duration	Lifelong
Types	N/A
Causes	Genetic mutation
Risks	Family history
Diagnosis	Genetic testing, blood test
Differential diagnosis	N/A
Prevention	N/A
Treatment	Glucocorticoids, antihypertensive drugs
Medication	N/A
Prognosis	N/A
Frequency	Rare
Deaths	N/A

Familial hyperaldosteronism type 1 (FH type 1), also known as glucocorticoid-remediable aldosteronism (GRA), is a rare genetic disorder characterized by the overproduction of the hormone aldosterone, which leads to hypertension (high blood pressure) and hypokalemia (low potassium levels). This condition is inherited in an autosomal dominant pattern, meaning that only one copy of the altered gene is sufficient to cause the disorder.

Pathophysiology

FH type 1 is caused by a genetic mutation that results in the fusion of the aldosterone synthase gene (CYP11B2) with the 11β-hydroxylase gene (CYP11B1). This fusion leads to the production of aldosterone in response to adrenocorticotropic hormone (ACTH), rather than the usual regulation by the renin-angiotensin system. As a result, aldosterone levels are inappropriately high, leading to increased sodium retention, potassium excretion, and hypertension.

Clinical Presentation

Patients with FH type 1 typically present with:

• Persistent hypertension that may be resistant to standard treatments.
• Hypokalemia, which can cause symptoms such as muscle weakness, fatigue, and arrhythmias.
• Family history of early-onset hypertension or stroke.

Diagnosis

The diagnosis of FH type 1 is confirmed through genetic testing, which identifies the specific gene fusion responsible for the condition. Blood tests may also reveal elevated aldosterone levels and suppressed plasma renin activity.

Treatment

The primary treatment for FH type 1 is the administration of low-dose glucocorticoids, such as dexamethasone or prednisone, which suppress ACTH production and subsequently reduce aldosterone levels. Additional antihypertensive medications, such as spironolactone or eplerenone, may be used to control blood pressure and correct hypokalemia.

Prognosis

With appropriate treatment, individuals with FH type 1 can manage their blood pressure effectively and reduce the risk of complications such as cardiovascular disease and stroke.

Also see

• Hypertension
• Hypokalemia
• Aldosterone
• Renin-angiotensin system
• Genetic testing