Autosomal dominant hypocalcemia type 1 (ADH1) carries a double burden of unmet need. Delayed diagnosis leaves patients exposed to years of unrecognized hypercalciuria and mounting risk of kidney damage. While conventional therapy may be necessary to treat the symptoms, it does not treat the underlying calcium‑sensing receptor (CaSR) dysfunction driving the disease.1-3
While symptoms may start in infancy, many people with ADH1 may not receive an accurate diagnosis until they are adults.
Patients may receive an incomplete diagnosis, including:
Patients may receive a misdiagnosis based on symptoms:
Early and accurate diagnosis is vital for treatment management and helping ensure favorable patient outcomes. For nonsurgical causes, an accurate diagnosis involves:
ICD‑10 for ADH1*The International Classification of Diseases, Tenth Revision (ICD‑10) code for ADH1 is E20.810.1*Example ICD‑10 codes do not suggest approval, coverage, or reimbursement for specific uses or indications.
Dig deeper: Patients with ADH1 experience more pronounced hypercalciuria when treated with conventional therapy (activated vitamin D and calcium supplements).4
This is due to the combined effects of low PTH and overly sensitive CaSR in the kidneys, leading to3,4:
Dig deeper: Approximately 20% of ADH1 cases occur spontaneously, with no family history, so don’t rule out ADH1 for patients with a medical history that is consistent with the biochemical features of ADH1.2
International guidelines and best practice recommendations by panel consensus recommend genetic testing for all patients with nonsurgical or idiopathic hypoparathyroidism.1,6
HypoPT is diagnosed via blood tests at least 2 weeks apart, confirming hypocalcemia and undetectable, low, or inappropriately normal PTH levels.
For accurate assessments:
Additional blood tests and urine analysis to aid in diagnosis include1,6,8:
eGFR=estimated glomerular filtration rate.
Due to the critical role of CaSR on the functions of the parathyroid gland and kidneys, patients with ADH1 often present with both hypocalcemia and hypercalciuria and may experience hypercalciuria‑associated complications2,5:
For people living with ADH1, the main goal with conventional therapy is to keep serum calcium concentrations close to, or slightly below, the lower limit of normal to avoid1-3:
Serum calcium
(albumin-adjusted or ionized)
Magnesium
Phosphorus
25-hydroxyvitamin D
Serum creatinine (for eGFR)
24-hour urine creatinine
24-hour urine calcium
Patients with ADH1 should be monitored regularly to assess their blood biochemistry and the risk of hypercalciuria and potential kidney damage.2,6
Currently, there are no medications specifically indicated to treat ADH1. There remains a substantial unmet need for therapies that address the underlying molecular mechanism of ADH1.1,2
The DetectHypopara™ Genetic Testing Program leverages a whole-exome backbone using next‑generation sequencing and includes 26 genes known to cause hypoparathyroidism, including CASR, with options to collect whole blood, saliva, or buccal specimens.
The program also partners with DNAvisit to offer no-cost genetic counseling to support healthcare professionals in helping their patients understand their genetic test results and identifying family members who may also be affected.
NOTE: Kits are provided at no cost and include prepaid return postage. Kits may take up to 1 week for delivery.
Genetic testing of the CASR gene can confirm ADH1 and inform disease management—but it works best in context. Rigorous laboratory assessment (with attention to assay limitations and testing interferences) and a thorough family history are essential considerations, remembering that roughly 20% of ADH1 cases arise with no family history at all.2,3
References: 1. Khan AA, Ali DS, Bilezikian JP, et al. Best practice recommendations for the diagnosis and management of hypoparathyroidism. Metabolism. 2025;171:156335. 2. Roszko KL, Stapleton Smith LM, Sridhar AV, et al. Autosomal dominant hypocalcemia type 1: a systematic review. J Bone Miner Res. 2022;37(10):1926-1935. doi:10.1002/jbmr.4659 3. Roszko KL, Bi RD, Mannstadt M. Autosomal dominant hypocalcemia (hypoparathyroidism) types 1 and 2. Front Physiol. 2016;7:458. 4. Mannstadt M, Cianferotti L, Gafni RI, et al. Hypoparathyroidism: genetics and diagnosis. J Bone Miner Res. 2022;37(12):2615-2629. 5. Pearce SH, Williamson C, Kifor O, et al. A familial syndrome of hypocalcemia with hypercalciuria due to mutations in the calcium-sensing receptor. N Engl J Med. 1996;335(15):1115-1122. 6. Bollerslev J, Buch O, Cardoso LM, et al. Revised European Society of Endocrinology clinical practice guideline: treatment of chronic hypoparathyroidism in adults. Eur J Endocrinol. 2025;193(5):G49-G78. 7. Bilezikian JP, Khan A, Potts JT Jr, et al. Hypoparathyroidism in the adult: epidemiology, diagnosis, pathophysiology, target-organ involvement, treatment, and challenges for future research. J Bone Miner Res. 2011;26(10):2317-2337. 8. Bollerslev J, Rejnmark L, Marcocci C, et al. European Society of Endocrinology clinical guideline: treatment of chronic hypoparathyroidism in adults. Eur J Endocrinol. 2015;173(2):G1-20.