Pseudohypoparathyroidism (patient information)

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Overview
Pseudohypoparathyroidism is a genetic disorder that is similar to hypoparathyroidism, but which results from the body's lack of response to parathyroid hormone rather than decreased production of the substance. There are three types of pseudohypoparathyroidism, type 1a, type 1b and type 2. All forms of pseudohypoparathyroidism are very rare and are caused by abnormal genes. Usual signs and symptoms include numbness, tetany, seizures, cataracts and dental problems. Patients with pseudohypoparathyroidism type 1a, which is also called Albright's hereditary osteodystrophy, may show signs of short stature. Blood tests of minerals, genetic testing and head MRI may help diagnose the disorder. Treatment for pseudohypoparathyroidism includes taking calcium carbonate and vitamin D supplements to normalize blood levels of calcium and phosphorus.

What are the symptoms of Pseudohypoparathyroidism?
There are three types of pseudohypoparathyroidism, type 1a, type 1b and type 2.
 * Signs and symptoms in type 1b and type 2
 * Numbness
 * Tetany
 * Seizures
 * Cataracts
 * Dental problems


 * Signs and symptoms in type 1a: Type 1a is inherited in an autosomal dominant manner and is also called Albright's hereditary osteodystrophy. Besides signs in type 1b and type 2, patients with type 1a may have the following symptoms:
 * Short stature: Round face, short neck, and short hand bones
 * Calcium deposits under the skin
 * Dimples that can replace knuckles on affected fingers

Diseases with similar symptoms
 * Hypoparathyroidism
 * Rickets

What causes Pseudohypoparathyroidism?
The parathyroid glands help control calcium use and removal by the body. They do this by producing parathyroid hormone, or PTH. PTH helps control calcium, phosphorus, and vitamin D levels within the blood and bone.

Persons with pseudohypoparathyroidism produce the right amount of PTH, but the body is "resistant" to its effect. This causes low blood calcium levels and high blood phosphate levels.

Pseudohypoparathyroidism is caused by abnormal genes. All forms of pseudohypoparathyroidism are very rare.

Type Ia is inherited in an autosomal dominant manner. That means only one parent needs to pass you the defective gene in order for you to develop the condition. The condition causes short stature, round face, and short hand bones, and is also called Albright's hereditary osteodystrophy.

Type Ib involves resistance to PTH only in the kidneys. Type Ib is less understood than type Ia. Type II is very similar to type I in its clinical features, but the events that take place in the kidneys are different.

Type II pseudohypoparathyroidism also involves low blood calcium and high blood phosphate levels, but persons with this form do not develop the physical characteristics seen in those with Type Ia.

All forms of pseudohypoparathyroidism are very rare.

Who is at highest risk?
All forms of pseudohypoparathyroidism are very rare. It is caused by abnormal genes. Researches demonstrate that type 1a is inherited in an autosomal dominant manner.

When to seek urgent medical care?
Call your health care provider if symptoms of pseudohypoparathyroidism develop. If you suffer either of the following symptoms, seeking urgent medical care as soon as possible:
 * Severe tetany
 * Seizures

Diagnosis

 * Blood tests: Patients with pseudohypoparathyroidism may indicate signs, such as low levels of blood-calcium, blood-magnesium and a high level of blood-phosphorus. The level of parathyroid hormone may ususally be normal.
 * Urine calcium test: Patients with pseudohypoparathyroidism may show much higher levels of urine calcium than normal.
 * Genetic testing: Genetic testing can find abnormal genes and allow the genetic diagnosis to inherit diseases like pseudohypoparathyroidism.
 * Head CT or MRI: Head imagings allow the doctor to distinguish abnormal development of pseudohypoparathyroidism from other endocrine diseases.

Treatment options
The goal of treatment for pseudohypoparathyroidism is to restore blood levels of calcium and phosphorus to normal. Calcium carbonate and vitamin D supplements are the only currently approved treatment.


 * Diet: Patients with pseudohypoparathyroidism are recommeded to take diets rich in calcium and low in phosphorus. Foods, such as green leafy vegetables, broccoli, kale, and fortified orange juice and breakfast cereals are appropriate. But patients had better not take many foods such as carbonated soft drinks, eggs and meats.
 * Calcium carbonate and vitamin D supplements: Low blood calcium in pseudohypoparathyroidism is usually milder than in other forms of hypoparathyroidism. Patients can take calcium and vitamin D as an oral supplement.

Where to find medical care for Pseudohypoparathyroidism?
Directions to Hospitals Treating pseudohypoparathyroidism

What to expect (Outlook/Prognosis)?
Low blood calcium in pseudohypoparathyroidism is usually milder than in other forms of hypoparathyroidism.

Possible complications
Patients with type Ia pseudohypoparathyroidism have an increased rate of other endocrine abnormalities (such as hypothyroidism and hypogonadism).

Complications of hypocalcemia associated with pseudohypoparathyroidism may include seizures and other endocrine problems, leading to lowered sexual drive and lowered sexual development, lowered energy levels, and increased weight.