SLC26A4 rs111033220: Understanding This Pendred Syndrome Variant
The rs111033220 variant is a rare genetic change located in the SLC26A4 gene. It is recognized as a pathogenic mutation associated with Pendred syndrome, a condition that can cause sensorineural hearing loss and thyroid abnormalities.
What each genotype means
Typical SLC26A4 genotype
This genotype represents the common, non-pathogenic sequence at this position. Individuals with this profile do not carry this specific mutation associated with Pendred syndrome or DFNB4 hearing loss.
This is the most common genotype observed in the general population.
Carrier of Pendred syndrome variant
This genotype indicates you are a carrier of a pathogenic mutation in the SLC26A4 gene. Because this condition is inherited in an autosomal recessive manner, carriers typically do not exhibit symptoms of Pendred syndrome or DFNB4, but should be aware of their carrier status for family planning.
This genotype is rare in the general population.
Associated with Pendred syndrome
This genotype is associated with an increased risk for Pendred syndrome or non-syndromic enlarged vestibular aqueduct (DFNB4). These conditions are characterized by sensorineural hearing loss and, in some cases, thyroid issues; clinical evaluation by a specialist is recommended for those with symptoms.
This genotype is very rare in the general population.
What is rs111033220?
The variant rs111033220 is a specific change in the DNA sequence of the SLC26A4 gene, often referred to in scientific literature as c.1229C>T or p.Thr410Met. Located on chromosome 7, this single nucleotide variant involves the substitution of one DNA building block for another. In the context of human genetics, this variant is classified as pathogenic, meaning it is known to disrupt the normal function of the gene in which it resides. Because it is a rare variant, it is not typically found in the general population at high frequencies. Geneticists study such variants to understand how specific alterations in our DNA code can lead to changes in protein structure and, subsequently, influence human health and development.
The Role of the SLC26A4 Gene
The SLC26A4 gene provides the instructions for the body to produce a protein called pendrin. Pendrin acts as an anion transporter, which means it helps move negatively charged ions, such as chloride, iodide, and bicarbonate, across the membranes of cells. This protein is particularly important in the inner ear and the thyroid gland. In the inner ear, pendrin helps maintain the delicate balance of fluids and ions necessary for normal hearing and balance. In the thyroid, it plays a role in the process of iodide transport, which is essential for the production of thyroid hormones. When the SLC26A4 gene contains a pathogenic mutation, the resulting pendrin protein may be non-functional or absent, leading to the clinical features associated with Pendred syndrome or non-syndromic hearing loss.
Research and Clinical Associations
Research has established a strong link between pathogenic variants in SLC26A4 and Pendred syndrome, an autosomal recessive disorder. This means that an individual typically needs to inherit two copies of a pathogenic variant—one from each parent—to manifest the full syndrome. The condition is characterized by sensorineural hearing loss, which is often present from birth or early childhood, and an enlarged vestibular aqueduct, an inner ear malformation. Some individuals also develop a goiter, which is an enlargement of the thyroid gland. While the evidence for the pathogenicity of this variant is well-documented in clinical databases, the severity of symptoms can vary significantly between individuals, even those with the same genotype. This variability suggests that other genetic or environmental factors may also influence how the condition presents.
Understanding Your Results
If you have received information about your status regarding rs111033220, it is important to understand that this is a carrier status variant. Being a carrier means you have one copy of the variant, which generally does not cause the symptoms of Pendred syndrome, as the condition is recessive. However, if both parents are carriers, there is a chance of passing the condition to their children. This information is for educational purposes and should not be used for self-diagnosis. If you are concerned about your genetic status or family history, the most appropriate step is to consult with a certified genetic counselor or a medical professional. They can provide context based on your specific health history and help you understand the implications of genetic testing results in a clinical setting.
How common is this variant?
The rs111033220 variant is considered rare in the general population. Its frequency varies by ancestry, and it is most commonly identified in clinical settings among individuals undergoing testing for hereditary hearing loss.
Frequently asked questions
What is Pendred syndrome?
Pendred syndrome is a genetic disorder that causes early hearing loss and can lead to thyroid enlargement. It is caused by mutations in the SLC26A4 gene.
Is rs111033220 the same as Pendred syndrome?
The variant rs111033220 is a specific mutation that can cause Pendred syndrome. However, having this variant does not automatically mean an individual has the syndrome, as it is a recessive condition.
What should I do if I am a carrier?
Being a carrier means you have one copy of the variant. You should discuss this result with a genetic counselor to understand the implications for your family planning and health.
Can this variant be treated?
There is no cure for the underlying genetic mutation. Management focuses on addressing the symptoms, such as using hearing aids or cochlear implants for hearing loss and monitoring thyroid function.
Sources & further reading
Educational information only, last refreshed 9/26/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This variant in the SLC26A4 gene is classified as pathogenic in ClinVar and is linked to hereditary hearing loss conditions.
This variant in the SLC26A4 gene is associated with Pendred syndrome and non-syndromic hearing loss.
This variant is associated with Pendred syndrome and non-syndromic hearing loss.