Pseudohypoparathyroidism - Causes, Symptoms, Complications, Diagnosis, and Treatment

Introduction:

Pseudohypoparathyroidism (PHP) is a genetic disorder in which the body does not respond to the parathyroid hormone (PTH) that is released by the parathyroid glands. It causes low calcium levels and high phosphorus levels in the blood. In PHP, the body produces the required amount of parathyroid hormone; however, it becomes unable to use. Calcium levels have to be maintained within ranges at all times for normal functioning of the body. Any imbalance can lead to symptoms.

What Is the Role of Calcium in the Body?

Calcium is the most vital element of our body that has its regulatory mechanism. The average calcium values in the blood are necessary for the proper functioning of the nerves and muscles apart from bone health.

The following are the functions of calcium in the body:

• Formation of solid teeth and bones.

• Contraction of muscles.

• Formation of blood clots.

• Channel for transmission of impulses along the nerves.

• Maintaining regular rhythmic activity of the heart.

The average calcium intake to maintain normal blood calcium levels and avoid resorption of bones is 1000 to 1500 milligrams of calcium per day.

What Is the Function of the Parathyroid Glands?

Parathyroid glands produce a hormone called parathyroid hormone or parathormone (PTH) that closely monitors the levels of calcium in the blood and bones. The parathyroid glands keep a minute-to-minute check on the blood calcium levels and release the PTH immediately when the calcium levels start falling.

What Are the Other Names of Pseudohypoparathyroidism?

• Types 1A and 1B pseudohypoparathyroidism.

• Albright hereditary osteodystrophy.

• PHP.

How Common Is Pseudohypoparathyroidism?

PHP is a rare condition that affects more than twice as many females as compared to males.

What Are the Causes of Pseudohypoparathyroidism?

PHP occurs due to the abnormality of genes. The condition is diagnosed in childhood and occurs in three types which include:

1. Type 1A.

2. Type 1B.

3. Type 2

Type 1A:

Type 1A can be inherited from any one of the parents having an abnormal gene. It is called an autosomal dominant inheritance pattern. Symptoms depend on whether the abnormal gene is inherited from the father or mother. Albright hereditary osteodystrophy is the other name for type 1A. The following signs and symptoms are noted in type 1A, which include:

• Round face.

• Short stature.

• Obesity.

• Short bones in hand.

• Delay in development.

Type 1B:

Type 1B occurs due to resistance to parathyroid hormone in the kidneys. In normal cases, kidneys respond to parathyroid hormone, which helps in the reabsorption of calcium from urine to retain it in the blood. In PHP, as kidneys do not respond to the hormone, low blood calcium levels occur. However, other characteristics of Albright hereditary syndrome do not occur in type 1b.

Type 2:

The gene abnormality that causes type 2 PHP is unknown. However, the condition presents with low blood calcium and high blood phosphorus levels. People affected with type 2 do not show the physical characteristics of type 1A.

What Are the Symptoms of Pseudohypoparathyroidism?

People affected with PHP usually have low blood calcium levels and high blood phosphorus and parathyroid hormone levels. The following symptoms due to low blood calcium are noticed, which include:

• Dental problems (teeth with underdeveloped enamel that erupt late).

• Cataract (a condition that affects the eye, causing clouding of the lens, which leads to impaired vision).

• Seizures.

• Numbness.

• Tetany (a bacterial infection that causes contractions of the muscles of the jaw and neck, along with foot and hand cramps).

• Headaches.

• Fatigue and lethargy.

• Impaired mental health.

People affected with Albright hereditary osteodystrophy may present with the following symptoms, which include:

• Round face.

• Short neck.

• Short bones in hand, particularly the bone beneath the fourth finger.

• Short stature.

• Calcium deposits under the skin.

• Dimples in the place of knuckles on fingers.

What Are the Complications of Pseudohypoparathyroidism?

People affected with type 1A can develop complications that occur due to the involvement of other endocrine (hormone-producing) glands.

The following complications are noted, which include:

1. Low energy.

2. Fatigue.

3. Weight gain.

4. Decrease in sex drive.

5. Slow sexual development.

6. Hypothyroidism (a condition in which the thyroid gland does not produce sufficient thyroid hormones).

7. Hypogonadism (a condition in which the body’s sex glands produce little or no sex hormones, estrogen, and testosterone).

How Is Pseudohypoparathyroidism Diagnosed?

The doctor may advise the following tests to diagnose PHP, which include:

• Blood Tests: Blood tests help determine the values of calcium, phosphorus, and parathyroid hormone in the blood.

• Urine Tests: Urine tests are done to know the levels of important ions like calcium and phosphorus in the urine.

• Genetic Testing: Testing for genetic abnormalities helps diagnose PHP and also the type of pseudohypoparathyroidism.

• Computerized Tomography (CT) Scan: CT scan creates cross-sectional images of the soft tissues by using several X-rays and computer processing. It helps detect calcium deposits in the brain.

• MRI (Magnetic Resonance Imaging) Scan: MRI is a non-invasive test that uses magnetic fields and radio waves to create detailed images of the brain.

How Is Pseudohypoparathyroidism Treated?

Doctors may recommend the usage of calcium and vitamin D supplements to correct low blood calcium levels. Vitamin D helps indirectly by increasing the absorption of calcium into the body. If the blood phosphorus levels are high, medicines like Phosphate binders (calcium carbonate or calcium acetate) are advised. Phosphate binders are used to reduce the number of phosphates absorbed from food. The dietitian may also recommend a diet low in phosphorus.

Some of the foods that are low in phosphorus include:

• Almond milk.

• Apples.

• Blueberries.

• Egg whites.

• Grapes.

• Lettuce.

• Macaroni.

• Non-dairy creamer.

• Pineapple.

• Pine nuts.

• Rice-bran oil.

• Sour cream.

People affected with PHP may be shorter than their peers. Growth hormone (GH) therapy is advised for such patients who show an improvement in height by the end of the first year of treatment.

Conclusion:

Pseudohypoparathyroidism (PHP) is a rare disorder that occurs due to abnormalities in the genes which are passed down from parents to their children. The patient may have low blood calcium levels that can cause short-term or long-term complications if left untreated. Calcium and vitamin D supplements have to be taken as prescribed by the doctor and to be taken lifelong. Also, a diet low in phosphorus is preferred. Regular monitoring of the blood levels of calcium, phosphorus, and parathyroid hormones is a must. Most people with PHP can lead normal lives with treatment.