Pendred syndrome is a disease that exists from birth. The condition is characterized by affected patients suffering from hearing loss. In addition, goiter is evident as part of Pendred syndrome.
What is Pendred syndrome?
Pendred syndrome is usually inherited, so affected individuals have had the condition since birth. Primarily, it is a disorder of hearing. Pendred syndrome is the most common syndromal disorder associated with hearing impairment. In addition, Pendred syndrome accounts for approximately five percent of all hearing impairments that are inherited. Pendred syndrome occurs with a frequency that varies by region. For example, the disease is much more common in Great Britain than in Scandinavian countries. In Germany, the frequency is also relatively low. Between four and ten percent of child patients who are deaf from birth have Pendred syndrome. The disease was first described by Pendred and received its name in reference to him. Basically, Pendred syndrome is characterized by a lack of the so-called thyroperoxidase. This is a specific enzyme that plays an important role in the metabolism of iodine in the thyroid gland. In addition, there is a genetic link between the disease and the so-called pendrin gene. This is located on the seventh chromosome and represents a protein responsible for the transport of iodine.
Causes
The reason for the development of Pendred syndrome is a genetic disorder. In this specific case, it is a mutation on a gene. The gene in question codes for a transporting protein called pendrin. The protein acts as a mediator between special anionic substances in the inner ear, the thyroid gland and the kidneys. Due to the genetic disorder, iodine transport into the follicles of the thyroid gland is impaired. As a result, the formation of thyroid hormones is disturbed. Basically, Pendred syndrome is inherited in an autosomal recessive way to possible offspring.
Symptoms, complaints, and signs
Pendred syndrome manifests itself in various complaints in affected patients. The main symptom is hearing loss, which is usually present in both ears. In the majority of cases, the hearing disorder already manifests itself in newborn infants. Some of the affected individuals also develop thyroid dysfunction. In some cases, goiter develops and hypothyroidism can be detected in the patients. With far less frequency, deformities of the inner ear are added to the symptoms of Pendred’s syndrome. In this case, for example, a widening of a special aqueduct can be seen. In most cases, the hearing loss manifests itself in the form of sensorineural hearing loss, which is usually severe. In addition, the disease is associated with a reduced cochlea. Since iodine is not properly processed in the thyroid gland, in many cases an underactive thyroid gland develops (medical term hypothyroidism). In young patients, the thyroid gland usually still functions largely normally.
Diagnosis and course of the disease
If symptoms or signs of disease resemble those of Pendred syndrome, an appropriate physician should be consulted as soon as possible. Often, the first signs appear in young children, so the pediatrician is usually consulted. If necessary, he or she will refer the affected patient to other specialists, such as a specialist in ear, nose and throat medicine or an endocrinologist. At the beginning of the diagnosis, an anamnesis is taken, which the treating physician conducts with the sick person and possibly with the parents or guardians. The focus is on the respective symptoms. Special attention is also paid to the family history, because Pendred syndrome is inherited and therefore shows a familial clustering. In addition, the patient is clinically examined in order to obtain information regarding the existing disease. Pendred syndrome, for example, can be diagnosed with relative certainty using the so-called perchlorate depletion test. In this test, radioactive iodine is used to check the processing of Job in the thyroid gland.In terms of differential diagnosis, thyroid insufficiencies that are not congenital play a decisive role. In addition, the physician checks whether Newell-Diddle syndrome or refetoff-de-Wind-de-Groot syndrome may be present. In addition, a CT scan or an MRI scan of the ear canal is usually performed. This is because potential malformations of the inner ear can be detected in this way. In the course of blood analyses, thyroid hormones are determined and their concentration interpreted. An elevated TSH value indicates the presence of hypothyroidism. In modern times, genetic analyses are also increasingly used, which usually confirm the diagnosis of Pendred syndrome.
Complications
Due to Pendred syndrome, patients primarily suffer from hearing loss. There are usually no other dangerous symptoms or complications, so the patient’s life expectancy is also usually not affected or limited by Pendred syndrome. Furthermore, in some cases there are also complaints of the thyroid gland, so that it can show an underactivity or an overactivity. This can lead to various other complaints, so that the thyroid gland must be treated in any case. On the ears, in some cases, there can also be deformities, so that the aesthetics of the patients can also be limited by this disease. The mental development of the child is usually not affected by the syndrome, so that even in adulthood there are usually no particular complaints. A causal treatment of Pendred’s syndrome is not possible, so that the hearing loss remains throughout life. Furthermore, the malfunctioning of the thyroid gland must be treated. However, no particular complications occur in this case either. The life expectancy of the affected person is not negatively affected by Pendred syndrome.
When should one go to the doctor?
In the case of Pendred syndrome, a visit to a doctor is necessary in any case, otherwise there will be no improvement in this disease. Since the disease usually occurs from birth, it is diagnosed immediately after it. A doctor should be consulted for Pendred syndrome if the affected person suffers from hearing complaints. These can vary in severity and can have a strong negative impact on the patient’s daily life and limit it. Furthermore, various malformations in the inner ear can lead to ear pain. If these complaints occur, the Pendred syndrome must be examined by a doctor in any case. Likewise, complaints of the thyroid gland can indicate Pendred syndrome, so that the thyroid gland should also be examined regularly when this syndrome occurs. Pendred syndrome is examined and treated by an otolaryngologist. Examination of the thyroid gland usually requires blood work, which can be examined by a primary care physician.
Treatment and therapy
Pendred syndrome represents a congenital disorder, so the disease is treated only symptomatically. This is because it is not possible to completely eliminate the genetic causes. Patients with the disease usually receive extensive support with regard to the development of their language skills. Hearing is also given special training. For example, numerous patients are prescribed logotherapy.
Outlook and prognosis
The prognosis in the presence of Pendred syndrome is not uniform. The effects of autosomal hereditary goiter hearing loss can vary in severity. In some cases, standard hearing aids are sufficient; in others, a cochlear implant must provide hearing improvements. Sufferers are at risk of progressive hearing loss if severe abnormalities have occurred in the inner ear. Besides implanting a cochlear implant, nothing more can be done for progressive hearing loss. Measures that help the hearing impaired person cope better with life are helpful. The thyroid disorders associated with Pendred syndrome, and the hypothyroidism that often develops from it, can be treated with medication. The prognosis is better if people affected by Pendred syndrome have only mild with moderate hearing loss. Also, the development of a goiter does not happen in every case with serious consequences. In many cases, goiter does not develop until adolescence or later.Hypothyroidism only develops if the diet contains too little iodine. Thus, something can be done early on to counteract some of the possible sequelae of Pendred’s syndrome. This improves the prognosis, so that in most cases a normal age can be reached despite all disabilities. The earlier those affected are introduced to hearing aids or sign language, the better prepared they will be for the deafness that may occur.
Prevention
Pendred syndrome is hereditary, so to the best of our current knowledge, there are no proven ways to prevent the disorder.
Follow-up
There are usually no special or direct measures and options of aftercare available to the affected person in Pendred syndrome. In this case, a doctor should ideally be consulted at a very early stage in order to prevent further complications or a further worsening of the symptoms. Self-cure is not possible, as this is a genetically determined disease. The affected person should therefore also contact a doctor if he or she wishes to have children, so that the syndrome is not passed on to the children. A doctor should be consulted at the first symptoms and signs of the disease. The affected children need the intensive support and care of their own family in their everyday lives. Loving conversations with their own family and with relatives or friends are also very important to prevent depression and other psychological upsets. The child should be familiarized with a hearing aid at an early age and learn sign language so that there are no special complications in everyday life. In Pendred syndrome, regular checkups and examinations by a doctor are also very important, although the syndrome does not usually reduce the life expectancy of the affected person.
What you can do yourself
People with Pendred syndrome should see an ear specialist or audiologist regularly. An otolaryngologist must monitor the progression and check for changes in hearing ability. Affected people with mild symptoms can compensate for hearing loss with a hearing aid. Severe hearing loss must be treated surgically by inserting an implant. Patients should ask their doctor about the various treatment options and make the necessary arrangements. After an ear surgery, the ear must be protected from drafts and moisture. It is recommended to wear a bathing cap for the first few days. In case of unusual complaints, the doctor must be consulted. Concomitant thyroid problems should be treated by a doctor. Sufferers can support the therapy with an adapted diet and exercise. In addition, it must be clarified whether certain medications such as cortisone or beta-blockers aggravate the symptoms. These preparations must be discontinued. If these measures are taken, Pendred’s syndrome can be treated effectively. Nevertheless, complaints may recur in the course of the disease, which must be clarified by a doctor. Patients are best to keep close consultation with their primary care physician.
