Pseudohypoparathyroidism

Pseudohypoparathyroidism (PHP) is a rare genetic disorder where your body doesn’t process parathyroid hormone (PTH), even though your parathyroid glands produce normal amounts of it.

Parathyroid hormone helps maintain calcium, phosphorus and vitamin D levels in your blood. PHP disrupts your body’s ability to use the hormones your parathyroid gland makes (parathyroid hormone resistance). As a result, the calcium levels in your blood drop and the phosphorus levels rise. This imbalance can lead to problems like muscle cramps, numbness, seizures and dental issues.

PHP is different from hypoparathyroidism. People with hypoparathyroidism don’t produce enough PTH to begin with.

Types of PHP

The different types are:

• PHP-1. This is the most common type. In addition to PTH resistance, PHP-1 causes skeletal abnormalities like a round face, short stature, short neck and shortened hand and foot bones. Healthcare providers call this set of symptoms Albright hereditary osteodystrophy (AHO). People with PHP-1 inherit the GNAS gene variant (change) from one of their biological parents.
• PPHP (pseudopseudohypoparathyroidism). This is a limited form of PHP-1. People with PPHP have physical symptoms of AHO but don’t have PTH resistance.
• PHP-2. People with PHP-2 have PTH resistance but lack the physical symptoms of AHO. Researchers don’t yet know which genetic abnormality causes PHP-2.

Symptoms of pseudohypoparathyroidism

Pseudohypoparathyroidism symptoms vary from person to person and may include:

• Muscle spasms
• Muscle cramps
• Numbness or tingling in your hands or feet
• Seizures
• Teeth that grow in later than expected
• Weakened tooth enamel
• Low blood pressure
• Brittle hair and nails
• Anxiety
• Brittle hair and nails
• Depression

People with PHP-1 also have Albright hereditary osteodystrophy (AHO). AHO and PHP features may include:

• Round face
• Short stature
• Short neck
• Shortened bones in your hands and feet
• Obesity
• Vision issues like cataracts, blurred vision or light sensitivity
• Bony bumps under your skin
• Developmental delays

Pseudohypoparathyroidism causes

Variations (changes) in your GNAS gene cause the disease. Some people inherit it from a biological parent. Others develop it for no known reason. PHP usually develops during infancy or childhood. But adults can get it, too.

Complications of pseudohypoparathyroidism

If you have PHP, you’re more likely to develop other endocrine system disorders. These hormonal issues can cause symptoms like low energy and low sex drive.

Some people with PHP are also more likely to develop:

• Parkinsonism
• Difficulty with fine motor skills
• Carpal tunnel syndrome (in people with PHP-1)
• Spinal stenosis
• Sleep apnea (in children)

How doctors diagnose pseudohypoparathyroidism

A healthcare provider will do a physical examination and review your family history. If they suspect the disease, they’ll likely run tests to confirm a diagnosis. These tests may include:

• Blood tests to measure hormone levels
• Urine tests (pee tests) to measure calcium and phosphorus levels
• Genetic testing for the GNAS gene
• Electrocardiogram (EKG) to check for an abnormal heart rhythm
• Hand X-rays to check for shortened bones
• CT (computed tomography) scan to look for differences in your brain

How is pseudohypoparathyroidism treated?

Treatment aims to restore and maintain proper levels of calcium and phosphorus in your blood. Managing these levels can help reduce your symptoms.

There’s no cure for the disease, but you can manage it with ongoing, lifelong treatment. Treatments may include:

• Calcium and vitamin D supplements
• Calcitriol capsules (a medication that increases calcium in your body)
• Calcitriol injections
• Growth or thyroid hormone replacement
• A high-calcium, low-phosphorus diet

When should I see my healthcare provider?

If you have PHP, see your healthcare provider regularly so they can monitor your calcium and phosphorus levels. Routine appointments can help things stay on track.

Call 911 or head to your nearest emergency room if you develop severe symptoms like difficulty breathing, painful muscle cramps or seizures.

What can I expect if I have pseudohypoparathyroidism?

If you have pseudohypoparathyroidism, you’ll receive ongoing care with your primary care physician. Because PHP can affect several parts of your body, you may also need to see specialists who can help manage your specific symptoms. Your healthcare team could include:

• Endocrinologists
• Orthopaedic surgeons
• Pediatricians
• Neurologists
• Physical therapists
• Occupational therapists
• Nutritionists
• Dentists
• Geneticists
• Pain management specialists

You’ll likely need to take supplements for the rest of your life.

Developmental and intellectual abilities vary significantly depending on the type and severity of the disease. In most cases, people with PHP have a normal life expectancy compared to people without PHP. Your healthcare provider can tell you what to expect.