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Pseudohypoparathyroidism Workup

  • Author: Mini R Abraham, MD; Chief Editor: George T Griffing, MD  more...
Updated: Dec 11, 2015

Approach Considerations

Laboratory studies for the diagnosis of pseudohypoparathyroidism (PHP) include serum calcium tests (including measurement of serum total calcium and ionized calcium) to confirm a hypocalcemic state. Serum phosphate levels are elevated in PHP.

Determining the serum concentration of intact PTH, using an immunoradiometric assay (IRMA), is also diagnostic.[9] When the serum concentration of PTH in a hypocalcemic patient is increased, the patient has either a form of PHP or secondary hyperparathyroidism.

Assessment of skeletal and renal responsiveness to PTH is accomplished by measurement of changes in serum calcium, phosphorus, cAMP, and calcitriol concentrations and in urinary cAMP and phosphorus excretion after administration of the biosynthetic N-terminal fragment of PTH.

Consider thyroid function tests and measurement of gonadotropin and testosterone or estrogen levels. Also consider assessment of growth hormone function with insulinlike growth factor-1.

In a study, Freson et al concluded that platelet-based testing can effectively be used in the diagnosis of Gsa defects. In their report, on the use of platelets to diagnose Gsa hypofunction, the investigators found that platelet aggregation responses varied according to Gsa signaling defects, thus providing a reflection of a patient's phenotype and genotype.[15]

A study by Todorova-Koteva et al demonstrated the use of commercially available recombinant PTH injections and concomitant measurement of cAMP in urine to diagnose PTH resistance, especially in nonphenotypically evident pseudohypoparathyroidism.[16]

Imaging studies

Radiography of the hand may show a specific pattern of shortening of the bones, in which the distal phalanx of the thumb and the third through fifth metacarpals are shortened most severely. Radiography may also show small soft tissue opacities (calcifications/ossifications). Computed tomography (CT) scanning may reveal calcification of the basal ganglia.

Other Tests

Additional studies in PHP include the following:

  • Electrocardiogram - May reveal prolongation of the QT interval secondary to hypocalcemia
  • Analysis of the GNAS1 gene - Helps to identify the specific genetic defect in patients with PHP type 1a

Patients with PHP type 1b[17] may be evaluated for parathyroid-related bone disease. Consider bone mineral density (BMD) testing in this group of patients.

Contributor Information and Disclosures

Mini R Abraham, MD Consulting Staff, Overland Park Medical Specialists

Mini R Abraham, MD is a member of the following medical societies: American Association of Clinical Endocrinologists, Endocrine Society

Disclosure: Nothing to disclose.


Romesh Khardori, MD, PhD, FACP Professor of Endocrinology, Director of Training Program, Division of Endocrinology, Diabetes and Metabolism, Strelitz Diabetes and Endocrine Disorders Institute, Department of Internal Medicine, Eastern Virginia Medical School

Romesh Khardori, MD, PhD, FACP is a member of the following medical societies: American Association of Clinical Endocrinologists, American College of Physicians, American Diabetes Association, Endocrine Society

Disclosure: Nothing to disclose.

Chief Editor

George T Griffing, MD Professor Emeritus of Medicine, St Louis University School of Medicine

George T Griffing, MD is a member of the following medical societies: American Association for the Advancement of Science, International Society for Clinical Densitometry, Southern Society for Clinical Investigation, American College of Medical Practice Executives, American Association for Physician Leadership, American College of Physicians, American Diabetes Association, American Federation for Medical Research, American Heart Association, Central Society for Clinical and Translational Research, Endocrine Society

Disclosure: Nothing to disclose.


Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

Stanley Wallach, MD Executive Director, American College of Nutrition; Clinical Professor, Department of Medicine, New York University School of Medicine

Stanley Wallach, MD is a member of the following medical societies: American College of Nutrition, American Society for Bone and Mineral Research, American Society for Clinical Investigation, American Society for Clinical Nutrition, American Society for Nutritional Sciences, Association of American Physicians, and Endocrine Society

Disclosure: Nothing to disclose.

Kent Wehmeier, MD Professor, Department of Internal Medicine, Division of Endocrinology, Diabetes, and Metabolism, St Louis University School of Medicine

Kent Wehmeier, MD is a member of the following medical societies: American Society of Hypertension, Endocrine Society, and International Society for Clinical Densitometry

Disclosure: Nothing to disclose.

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Patient with pseudohypoparathyroidism showing shortened fourth metacarpals.
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