Goiter is an enlargement of the thyroid gland. The thyroid gland is the largest endocrine organ in our body. It is located in our neck, in the anterior lower region of the trachea, close to the sternum. It secretes thyroid hormones. The thyroid gland measures 4-4.8 cm from top to bottom, 1-1.8 cm in width, and 0.8-1.6 cm from front to back.
Pendred syndrome is a syndrome in which hearing loss is seen together with goiter. Pendred syndrome is an autosomal recessive genetic disease caused by mutation in the gene encoding the pendrin protein. The hearing loss in Pendred syndrome is usually bilateral. There is usually little or no balance disorder.
Pendred syndrome is responsible for approximately 10% of congenital hearing loss cases. Pendrin protein is an important protein involved in the resorption of inner ear fluid. It has an important function in the regular functioning of the inner ear and in the acid-base balance of the ear. It provides the balance of bicarbonate and chloride. Defects in Pendrin protein can also cause metabolic alkalosis. This metabolic alkalosis can be life-threatening.
Pendrin protein also plays a role in regulating the thickness of the surface fluid in the airways. Therefore, it has an important role in asthma and COPD diseases.
Although there is a goiter in Pendred syndrome, thyroid hormone balance is provided. Most patients have a congenital goiter. Some patients may have hypothyroidism without clinical symptoms.
Diagnosis of Pendred syndrome:
Molecular genetic testing is used for diagnosis in Pendred syndrome. To examine the structure of the inner ear, the temporal bone structure can be evaluated with CT. The thyroid hormone profile is usually normal. Goiter can be evaluated with thyroid ultrasonography.
The goiter detected in Pendred syndrome is usually euthyroid. Sometimes it can be seen together with autoimmune thyroiditis.
Treatment of Pendred’s syndrome:
There is no definitive treatment for Pendred’s syndrome. Multidisciplinary follow-up is done. Hearing aids or cochlear implants can be applied for hearing loss. Thyroid functions and dimensions of the thyroid gland are monitored regularly. Treatment is planned according to the clinical picture.
Other causes of goiter should be evaluated along with other causes of hearing impairment. Pendred syndrome progresses with progressive hearing loss. In the process, hypothyroidism may develop. In patients who develop hypothyroidism, treatment planning is made according to clinical and laboratory findings.