Overview
Neonatal severe primary hyperparathyroidism (NSHPT) is a rare, life-threatening endocrine disorder characterized by markedly elevated parathyroid hormone (PTH) levels and severe hypercalcemia presenting in the first days to weeks of life. It is caused by homozygous or compound heterozygous inactivating mutations in the CASR gene, which encodes the calcium-sensing receptor. This receptor plays a critical role in regulating calcium homeostasis by detecting blood calcium levels and modulating PTH secretion from the parathyroid glands. When the receptor is severely impaired, the parathyroid glands fail to recognize elevated calcium levels and continue to secrete excessive PTH, leading to dangerously high blood calcium. The condition primarily affects the skeletal, renal, and neurological systems. Key clinical features include severe hypercalcemia, marked elevation of PTH, skeletal demineralization (including fractures, subperiosteal bone resorption, and rachitic changes), hypotonia, respiratory distress, failure to thrive, dehydration, constipation, and polyuria. Parathyroid gland hyperplasia is a hallmark finding. Without prompt treatment, the condition can be fatal due to complications of extreme hypercalcemia, including cardiac arrhythmias and respiratory failure. Treatment of NSHPT is considered a medical emergency. Initial management involves aggressive intravenous hydration and medications to lower calcium levels, such as bisphosphonates and calcitonin. However, the definitive treatment is total parathyroidectomy (surgical removal of all parathyroid glands), which is typically required urgently in the neonatal period. Following surgery, patients require lifelong calcium and vitamin D supplementation to manage the resulting hypoparathyroidism. In some cases with less severe presentations due to heterozygous CASR mutations, a milder phenotype may occur, and calcimimetic agents such as cinacalcet have been used with some success.
Also known as:
Clinical phenotype terms— hover any for plain English:
Autosomal recessive
Passed on when both parents carry the same gene change; often skips generations
Neonatal
Begins at or shortly after birth (first 4 weeks)
Treatments
No FDA-approved treatments are currently listed for Neonatal severe primary hyperparathyroidism.
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Specialists
View all specialists →No specialists are currently listed for Neonatal severe primary hyperparathyroidism.
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
Financial Resources
1 resourcesZemplar
AbbVie
Secondary Hyperparathyroidism
Travel Grants
No travel grants are currently matched to Neonatal severe primary hyperparathyroidism.
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Common questions about Neonatal severe primary hyperparathyroidism
What is Neonatal severe primary hyperparathyroidism?
Neonatal severe primary hyperparathyroidism (NSHPT) is a rare, life-threatening endocrine disorder characterized by markedly elevated parathyroid hormone (PTH) levels and severe hypercalcemia presenting in the first days to weeks of life. It is caused by homozygous or compound heterozygous inactivating mutations in the CASR gene, which encodes the calcium-sensing receptor. This receptor plays a critical role in regulating calcium homeostasis by detecting blood calcium levels and modulating PTH secretion from the parathyroid glands. When the receptor is severely impaired, the parathyroid glands
How is Neonatal severe primary hyperparathyroidism inherited?
Neonatal severe primary hyperparathyroidism follows a autosomal recessive inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Neonatal severe primary hyperparathyroidism typically begin?
Typical onset of Neonatal severe primary hyperparathyroidism is neonatal. Age of onset can vary across affected individuals.
What treatment and support options exist for Neonatal severe primary hyperparathyroidism?
1 patient support program are currently tracked on UniteRare for Neonatal severe primary hyperparathyroidism. See the treatments and support programs sections for copay assistance, eligibility, and contact details.