Overview
Familial hyperphosphatemic tumoral calcinosis (HFTC), also known as hyperphosphatemic hyperostosis syndrome (HHS), is a rare inherited condition that causes the body to retain too much phosphate in the blood. Normally, the kidneys filter out excess phosphate, but in this disease, the kidneys reabsorb too much phosphate back into the bloodstream. This leads to abnormally high phosphate levels (hyperphosphatemia), which in turn causes calcium and phosphate to deposit in soft tissues throughout the body, forming large, sometimes painful masses called tumoral calcinosis. These masses most commonly appear around major joints such as the hips, shoulders, elbows, and knees, and can limit movement and cause significant discomfort. In the hyperostosis form, patients may also develop abnormal bone overgrowth, particularly in the long bones and the skull. Some patients experience both tumoral calcinosis and hyperostosis. The disease can also cause dental problems, including abnormalities of the tooth roots and gums. Skin involvement may include a rash or small calcified nodules. Treatment focuses on lowering phosphate levels through a low-phosphate diet and phosphate-binding medications. Surgical removal of calcium deposits may be needed when they cause pain or limit joint movement, though deposits can recur. There is currently no cure, and management is lifelong. Early diagnosis and consistent treatment can help reduce the severity of symptoms and improve quality of life.
Also known as:
Key symptoms:
Large firm masses around joints (tumoral calcinosis)Joint pain and stiffnessLimited range of motion in affected jointsHigh phosphate levels in the bloodBone overgrowth (hyperostosis)Swelling around hips, shoulders, elbows, or kneesSkin rash or small hard bumps under the skinDental abnormalities such as short tooth rootsGum overgrowth or inflammationEye redness or calcification (eyelid calcification)Recurrent masses after surgical removalDifficulty moving affected limbsPain when pressure is applied to the masses
Autosomal recessive
Passed on when both parents carry the same gene change; often skips generations
Variable
Can begin at different ages, from infancy through adulthood
Treatments
No FDA-approved treatments are currently listed for Familial hyperphosphatemic tumoral calcinosis/Hyperphosphatemic hyperostosis syndrome.
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Specialists
View all specialists →No specialists are currently listed for Familial hyperphosphatemic tumoral calcinosis/Hyperphosphatemic hyperostosis syndrome.
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 hyperphosphatemic tumoral calcinosis/Hyperphosphatemic hyperostosis syndrome.
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Caregiver Resources
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Mental Health Support
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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.Which gene mutation is causing my condition, and does this affect my treatment options?,How strictly do I need to follow a low-phosphate diet, and can I see a dietitian who specializes in this?,How often should my blood phosphate and calcium levels be checked?,When should surgery be considered for the calcified masses, and what is the chance they will come back?,Are there any clinical trials or new treatments being studied for this condition?,What should I watch for that would require urgent medical attention?,Should my family members be tested for this condition?
Common questions about Familial hyperphosphatemic tumoral calcinosis/Hyperphosphatemic hyperostosis syndrome
What is Familial hyperphosphatemic tumoral calcinosis/Hyperphosphatemic hyperostosis syndrome?
Familial hyperphosphatemic tumoral calcinosis (HFTC), also known as hyperphosphatemic hyperostosis syndrome (HHS), is a rare inherited condition that causes the body to retain too much phosphate in the blood. Normally, the kidneys filter out excess phosphate, but in this disease, the kidneys reabsorb too much phosphate back into the bloodstream. This leads to abnormally high phosphate levels (hyperphosphatemia), which in turn causes calcium and phosphate to deposit in soft tissues throughout the body, forming large, sometimes painful masses called tumoral calcinosis. These masses most commonly
How is Familial hyperphosphatemic tumoral calcinosis/Hyperphosphatemic hyperostosis syndrome inherited?
Familial hyperphosphatemic tumoral calcinosis/Hyperphosphatemic hyperostosis syndrome follows a autosomal recessive inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.