What is pseudohyperthyroidism? What are the symptoms? How can it be treated?

We all know that the thyroid gland is the largest endocrine gland in the human body, and it plays a large role in endocrine regulation and distribution in our body. So what is pseudohyperthyroidism?

Causes

The parathyroid gland is located behind the thyroid gland in the neck. Although it belongs to the same endocrine system as the thyroid gland, it secretes different hormones and has different functions. The main function of the parathyroid gland is to secrete parathyroid hormone (PTH), which promotes the release of calcium ions from the intestines, bones, and renal tubules into the blood, while increasing the excretion of phosphorus in the urine to maintain the balance of calcium and phosphorus in the blood. The main cause of hypothyroidism is the incomplete development of the parathyroid gland itself or the inadvertent removal of the neck during surgery.

Patients with pseudohypoparathyroidism (PHP) mainly have defects in the Gαs protein gene at position 20q13.2, which leads to abnormal expression of Gαs protein and causes resistance of the organs where parathyroid hormone (PTH) should act to PTH.

Pseudo-hypoparathyroidism can be further divided into three types according to the defects in different positions of the GNAS1 gene and different clinical symptoms: PHP type Ia, PHP type Ib and pseudo-pseudohypoparathyroidism (P-PHP).

Symptoms

Due to abnormal Gαs protein, patients cannot respond to PTH's instructions, so PTH cannot play a role in the organs, causing the PTH value in the blood to rise, leading to low blood calcium and high blood phosphorus; patients may experience paresthesia, muscle spasms, stiffness, convulsions and other symptoms. In addition, there are different clinical symptoms according to the disease type:

PHP-Ia:

Patients with this type of dysplasia have characteristics such as short stature, obesity, round face, subcutaneous ossification and short fingers (especially on the palms and metatarsals), so it is also called Albright hereditary osteodystrophy (AHO).

Since this disease is caused by abnormalities in Gαs protein, other hormones related to Gαs protein may also show symptoms of insufficient function; these hormones related to Gαs protein include: thyroid-stimulating hormone (TSH), antidiuretic hormone, gonadotropins, glucagon, etc., which may cause problems such as hypothyroidism and infertility.

P-PHP:

It usually occurs in the offspring of PHP-Ia patients. This type of patients only have clinical symptoms of AHO and no other endocrine hormone abnormalities.

PHP-Ib:

This type of patient has no clinical symptoms of AHO and no abnormalities in other endocrine hormones. The patient's main problem is that the kidneys are resistant to PTH, resulting in symptoms of low blood calcium; the severity may vary within the same family.

Diagnosis

Laboratory inspection:

In addition to monitoring the patient's blood calcium and phosphorus levels, in terms of disease classification, the patient also needs to test TSH, antidiuretic hormone, gonadotropins, glucagon, etc.

X-ray examination:

In AHO, the fourth and fifth phalanges of the terminal phalanges of the hand may be abnormally short, and soft tissue ossification may also occur.

Genetic testing:

Blood can be drawn and tested using molecular biological technology to determine if the patient has the defective GNAS1 gene.

treatment

The goal of treatment is to maintain the balance of calcium and phosphorus in the patient's body. Patients usually need to take calcium tablets and active vitamin D3 (Calcitriol) orally and have blood drawn regularly for monitoring. When severe hypocalcemia occurs, calcium can be supplemented through intravenous injection, but the speed should not be too fast to avoid causing heart conduction abnormalities.