Causes And Diagnosis Of Pendred Syndrome

Pendred syndrome may seem like a rare disease for a fact that it is not commonly heard of. However, if you want to know what this thyroid disorder is all about, it pays to look at its causes and how it is diagnosed as well.

After reading an overview of Pendred syndrome and its characteristics, you might as well want to know the causes of this condition. Below you will also learn several procedures to help you diagnose this genetic condition. This will make you understand more about the prevalence of this disease. Feel free to browse along this page.

What causes Pendred syndrome?

Since Pendred syndrome is a genetic disease, mutations in the DNA chromosomes is the usual cause. Mutation is defined as the chemical alteration in the genes of our cells to produce a new characteristic. It often produces evolutional changes or in some cases, diseases. In the case of a mutated PDS gene it is the latter.

The SLC26A4 gene normally provides instructions for making a protein called pendrin. Pendrin transports ions such as chloride and bicarbonates across cell membranes. It is found in kidneys, inner ear and thyroid. Since the gene is mutated, normal functions of the ear (hearing, maintaining balance and orientation) and thyroid (enlargement or goiter) are affected.

The mutated PDS gene or SLC26A4 gene found in the chromosome 7 is inherited in the autosomal recessive manner as described earlier. The child inherits two mutated SLC26A4 gene from each parent to have Pendred syndrome. Genetic testing is often advised for individuals who might develop the disease itself or pass it on to their offspring.

Couples who fear that their children might inherit Pendred syndrome are encouraged to take genetic screening tests. Since genetic testing are complex procedures, couples are given genetic counsellors that act as a support group. It is the task of the counsellors to provide advices as to the likelihood of their children being born with genetic disorder.

How is Pendred Syndrome diagnosed?

In order to diagnose Pendred syndrome properly, an otolaryngologist and clinical geneticist consider the person’s hearing, inner ear structures and sometimes the thyroid functions. Below are the different procedure used to diagnose this thyroid disorder”

·         Audiology tests. This is to measure the individuals’ ability to hear sounds at different pitches. The results may be abnormal therefore it is not a definitive test to diagnose Pendred syndrome. The specialist at this time may also evaluate the onset, duration and pattern of hearing loss.

·         Imaging Techniques. Magnetic Resonance Imaging (MRI) or Computed Tomography (CT or CAT scan) are procedures commonly used to obtain images of the inner ear. During these tests, two key characteristics of Pendred syndrome are seen. First is the cochlea (the spiral shaped part of the inner ear) has few turns. Second, the vestibular ducts may be enlarged.

·         Perchlorate Washout Test. This is the best test to determine the thyroid’s normal functions.

·         Genetic Testing. This is a screening test for individuals whose genes are associated with a genetic disorder like Pendred syndrome.

The causes and procedures stated above might as well help couples who might pass on to their offspring the mutated genes. It is always imperative to contact a geneticist to further understand the disease itself. The support they give to individuals during counselling will help them deal with such complex disorder. They help weigh your options and also provide emotional support.