Overview
Familial hyperaldosteronism type II (FH-II) is a rare inherited condition where the adrenal glands — two small glands that sit on top of the kidneys — produce too much of a hormone called aldosterone. This overproduction is called primary aldosteronism or hyperaldosteronism. Unlike some other forms of familial hyperaldosteronism, FH-II is not suppressed by a steroid medication called dexamethasone, which helps doctors tell it apart from related conditions. When aldosterone levels are too high, the body holds onto too much sodium and loses too much potassium. This throws off the balance of salts in the blood and causes high blood pressure (hypertension) that is often difficult to control with standard medications. Low potassium levels (hypokalemia) can cause muscle weakness, cramps, fatigue, and heart rhythm problems. Many people with FH-II are diagnosed after their doctor notices persistently high blood pressure at a relatively young age, sometimes in childhood or early adulthood. The condition can be caused by a benign (non-cancerous) tumor on one or both adrenal glands, or by the adrenal glands simply being overactive without a visible tumor. Treatment depends on the cause: surgery to remove an affected adrenal gland can be curative in some cases, while medications that block aldosterone's effects — such as spironolactone or eplerenone — are used when surgery is not an option or when both glands are involved. With proper treatment, blood pressure can usually be well controlled and serious complications can be prevented.
Also known as:
Key symptoms:
High blood pressure that is hard to controlLow potassium levels in the bloodMuscle weakness or crampsFatigue and tirednessFrequent urination or increased thirstHeadachesHeart palpitations or irregular heartbeatNumbness or tingling in the hands and feetConstipationGeneral feeling of being unwell
Clinical phenotype terms (14)— hover any for plain English
Autosomal dominant
Passed on from just one parent; each child has about a 50% chance of inheriting it
Variable
Can begin at different ages, from infancy through adulthood
Treatments
No FDA-approved treatments are currently listed for Familial hyperaldosteronism type II.
View clinical trials →Clinical Trials
View all trials with filters →No actively recruiting trials found for Familial hyperaldosteronism type II at this time.
New trials open frequently. Follow this disease to get notified.
Specialists
View all specialists →No specialists are currently listed for Familial hyperaldosteronism type II.
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Familial hyperaldosteronism type II.
Community
No community posts yet. Be the first to share your experience with Familial hyperaldosteronism type II.
Start the conversation →Latest news about Familial hyperaldosteronism type II
No recent news articles for Familial hyperaldosteronism type II.
Follow this condition to be notified when news becomes available.
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.Should I have genetic testing for the CLCN2 gene, and should my family members be tested too?,Do I need adrenal vein sampling to find out if one or both of my adrenal glands are affected?,Am I a candidate for surgery, and what are the chances it would cure my high blood pressure?,What are the risks of long-term use of spironolactone or eplerenone, and are there alternatives?,How often do I need blood tests and check-ups to monitor my condition?,What symptoms should prompt me to go to the emergency room?,What does this diagnosis mean for my children or siblings — should they be screened?
Common questions about Familial hyperaldosteronism type II
What is Familial hyperaldosteronism type II?
Familial hyperaldosteronism type II (FH-II) is a rare inherited condition where the adrenal glands — two small glands that sit on top of the kidneys — produce too much of a hormone called aldosterone. This overproduction is called primary aldosteronism or hyperaldosteronism. Unlike some other forms of familial hyperaldosteronism, FH-II is not suppressed by a steroid medication called dexamethasone, which helps doctors tell it apart from related conditions. When aldosterone levels are too high, the body holds onto too much sodium and loses too much potassium. This throws off the balance of sal
How is Familial hyperaldosteronism type II inherited?
Familial hyperaldosteronism type II follows a autosomal dominant inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.