The information on this website is not intended for diagnosis or treatment. Please consult your physician for health concerns.

+90 850 321 50 00

Pseudohypoparathyroidism

PTH Resistance Syndromes and Albright Hereditary Osteodystrophy

Written by: Saygı Hospital Health Guide Editorial Board
Last updated:

This content has been compiled by the Saygı Hospital Health Guide Editorial Board and is periodically reviewed by a specialist physician.

References (5)

This content is for informational purposes only and does not constitute medical advice. You can book an appointment at our Endokrinoloji department. Book Appointment →

What is Pseudohypoparathyroidism?

Pseudohypoparathyroidism (PHP) refers to inherited disorders characterized by end-organ resistance to parathyroid hormone, leading to hypocalcemia and hyperphosphatemia despite elevated endogenous PTH levels.

Caused predominantly by inactivating mutations or epigenetic defects in the GNAS gene, encoding the alpha-subunit of stimulatory G-protein (Gsα).

Classified into PHP type 1A (AHO + multi-hormone resistance), 1B (isolated PTH resistance, GNAS methylation defect), 1C (AHO without Gsα deficiency), and type 2 (post-receptor cAMP defect).

Diagnosis is biochemical (low calcium, high phosphate, high PTH) with confirmatory GNAS molecular testing and Ellsworth-Howard test (urinary cAMP response to exogenous PTH).

Symptoms

Hypocalcemic features: paresthesias, perioral numbness, muscle cramps, carpopedal spasm (Trousseau, Chvostek signs)
Tetany, laryngospasm, and hypocalcemic seizures in severe cases
Albright hereditary osteodystrophy phenotype: short stature, round face, obesity, brachydactyly (especially 4th and 5th metacarpals), subcutaneous ossifications
Developmental delay and intellectual disability in PHP-1A
Multi-hormone resistance manifestations: hypothyroidism (TSH resistance), hypogonadism (gonadotropin resistance), growth hormone deficiency
Basal ganglia calcifications and cataracts on imaging in chronic disease

Risk Factors

Maternally inherited GNAS mutation (PHP-1A) versus paternally inherited (pseudo-pseudohypoparathyroidism)
Family history of AHO phenotype, hypocalcemia, or unexplained tetany
Sporadic GNAS methylation defects in PHP-1B
Imprinted gene expression dictates phenotypic expression
Female sex slightly more affected by full PHP-1A phenotype

When to See a Doctor?

If you experience any of the following symptoms, seek medical attention promptly:

  • Recurrent muscle cramps, perioral tingling, or unexplained tetany
  • Children with short stature, brachydactyly, or developmental delay with hypocalcemia
  • Family member with confirmed PHP for genetic counseling and screening
  • Basal ganglia calcifications or unexplained cataracts on neuroimaging

Treatment Methods

01
Active vitamin D analogs: calcitriol 0.25–2 mcg/day or alfacalcidol, titrated to maintain low-normal serum calcium and PTH within 1–2× upper limit
02
Oral calcium supplementation: elemental calcium 1–3 g/day in divided doses (calcium carbonate or citrate)
03
Phosphate binders (calcium carbonate at meals) for hyperphosphatemia control
04
Levothyroxine replacement for TSH resistance (PHP-1A) and sex hormone replacement for hypogonadism
05
Recombinant growth hormone for documented GH deficiency in pediatric patients
06
Long-term monitoring: serum calcium, phosphate, PTH every 3–6 months; 24-hour urine calcium to prevent nephrocalcinosis; renal ultrasound and ophthalmologic surveillance
07
Genetic counseling for affected families and prenatal diagnosis when GNAS mutation is identified

Which Department to Visit?

You can visit our Endokrinoloji department for these complaints. Our specialist physicians will create the most suitable treatment plan for you.

Learn About Endokrinoloji Department

Let us help you

You can make an appointment with our specialists or contact us for your concerns.

Book AppointmentContact Us

Related Health Topics

Other articles from the same department you may want to explore.

Anaemia

Dahiliye (İç Hastalıkları)

Anaemia is a low haemoglobin level that reduces oxygen delivery, causing fatigue, pallor, and shortness of breath. It is not a disease itself but a sign of many underlying conditions. Most cases are correctable with appropriate diagnosis and treatment.

Iron Deficiency Anaemia

Dahiliye (İç Hastalıkları)

Iron deficiency anaemia develops when dietary intake, absorption, or losses create an iron shortfall, most often affecting women and children. Identifying the underlying cause is the core of management, alongside iron replacement.

Vitamin B12 Deficiency

Dahiliye (İç Hastalıkları)

Vitamin B12 deficiency can cause megaloblastic anaemia, neurological symptoms, and cognitive impairment. Early treatment with intramuscular or oral B12 largely prevents irreversible complications.

Hypertension (High Blood Pressure) Management

Dahiliye (İç Hastalıkları)

Hypertension is often called the silent killer because it progresses symptom-free for years and can damage the heart, brain, kidneys, and eyes. Regular monitoring, lifestyle change, and evidence-based drug therapy dramatically reduce cardiovascular risk.

Chronic Kidney Disease

Dahiliye (İç Hastalıkları)

Chronic kidney disease is one of the most common complications of chronic conditions such as diabetes and hypertension, and can be silent in its early stages.

Hepatitis B (HBV)

Dahiliye (İç Hastalıkları)

Hepatitis B is a DNA virus infection causing acute and chronic hepatitis with risk of cirrhosis and hepatocellular carcinoma; diagnosis integrates HBsAg, HBeAg, anti-HBc, and HBV DNA with management based on disease phase using nucleos(t)ide analogues (entecavir, tenofovir) and universal infant vaccination.

Hepatitis C (HCV)

Dahiliye (İç Hastalıkları)

Hepatitis C is an RNA virus causing chronic hepatitis that may progress to cirrhosis and hepatocellular carcinoma; modern direct-acting antiviral (DAA) pangenotypic regimens (sofosbuvir/velpatasvir, glecaprevir/pibrentasvir) achieve sustained virologic response over 95% in 8–12 weeks with universal adult screening and cure for nearly all patients.

Fatty Liver Disease

Dahiliye (İç Hastalıkları)

Non-alcoholic fatty liver disease (NAFLD) is closely related to obesity and metabolic syndrome and is largely reversible with early treatment.

Health Disclaimer: The information on this page is prepared for general informational purposes only. It does not replace medical diagnosis and treatment. Please consult your physician for your complaints. Saygı Hospital does not accept responsibility for actions taken based on the information on this page.