GJB2 rs111033620: Understanding This Genetic Variant
The rs111033620 variant is a single nucleotide deletion within the GJB2 gene, often referred to as c.235delC. It is recognized as a pathogenic variant associated with autosomal recessive non-syndromic sensorineural hearing loss.
What each genotype means
Typical GJB2 genotype
This genotype represents the absence of the c.235delC variant in the GJB2 gene. Individuals with this result do not carry this specific mutation associated with autosomal recessive non-syndromic hearing loss.
This is the most common genotype observed across all global populations.
Carrier of hearing loss variant
This genotype indicates you are a carrier of the c.235delC (p.Leu79CysfsTer41) variant. Carriers typically do not experience hearing loss related to this variant, but there is a chance of passing the variant to offspring, which may be relevant if a partner also carries a pathogenic GJB2 variant.
Carried by approximately 0.7% to 1.0% of individuals in East Asian populations.
Increased risk of hearing loss
This genotype indicates the presence of two copies of the c.235delC variant. This variant is a known pathogenic mutation associated with autosomal recessive non-syndromic sensorineural hearing loss, particularly in East Asian populations. Clinical correlation with hearing status is recommended.
This genotype is rare, occurring at a frequency consistent with the square of the carrier allele frequency in specific East Asian populations.
What is the rs111033620 Variant?
The rs111033620 variant is a specific genetic change located in the GJB2 gene. In scientific literature, this is frequently identified by the nomenclature c.235delC, which describes a deletion of a single cytosine nucleotide at position 235 of the gene's coding sequence. This deletion causes a frameshift, meaning it alters the way the cellular machinery reads the genetic code downstream from the mutation. This shift typically leads to a premature stop codon, resulting in a truncated and non-functional protein. Because this variant disrupts the normal production of the protein, it is classified as a pathogenic variant in clinical databases. It is important to note that this variant is primarily studied in the context of hereditary hearing loss, and its presence is a subject of significant interest in clinical genetics, particularly for families with a history of congenital hearing impairment.
The Role of the GJB2 Gene
The GJB2 gene provides instructions for making a protein called connexin 26. This protein is a member of the connexin family, which forms channels called gap junctions that allow for the transport of ions and small molecules between adjacent cells. In the inner ear, these gap junctions are essential for maintaining the chemical environment necessary for the function of hair cells, which are the sensory cells responsible for converting sound vibrations into electrical signals for the brain. When GJB2 is mutated, the resulting connexin 26 protein may be absent or dysfunctional, disrupting the communication between cells in the cochlea. This disruption can prevent the inner ear from functioning correctly, leading to sensorineural hearing loss. Because the gene is involved in such a fundamental biological process, variants that significantly alter the protein structure often have a direct impact on auditory health.
Research and Clinical Associations
Research has established a strong association between the c.235delC variant (rs111033620) and autosomal recessive non-syndromic sensorineural hearing loss. In an autosomal recessive condition, an individual typically needs to inherit two copies of the pathogenic variant—one from each parent—to manifest the hearing loss phenotype. Individuals who carry only one copy of the variant are generally considered carriers and typically do not exhibit hearing loss, though they can pass the variant to their offspring. The evidence for this variant's pathogenicity is well-supported by clinical studies, particularly in East Asian populations where it is a known founder mutation. While the association with hearing loss is clear, the severity and onset of the condition can vary between individuals, even among those with the same genotype. Clinicians use this information to provide genetic counseling for families, helping them understand the risks of passing the variant to future generations.
What You Can Do With This Information
Genetic information regarding variants like rs111033620 is intended for educational and informational purposes. If you have received results indicating you are a carrier of this variant, it does not mean you have a medical condition or that you will experience hearing loss. Instead, it provides insight into your genetic makeup that may be relevant for family planning. If you are concerned about your hearing or your family's genetic history, the most appropriate step is to consult with a qualified healthcare provider or a genetic counselor. They can help interpret your results in the context of your personal and family health history. Never use genetic test results to make independent medical decisions or to diagnose yourself. Always discuss any findings with a professional who can provide personalized guidance and, if necessary, refer you to an audiologist or other specialists for further evaluation.
How common is this variant?
The rs111033620 variant is most prevalent in East Asian populations, with allele frequencies typically ranging from 0.007 to 0.01 in gnomAD datasets.
Frequently asked questions
Is rs111033620 the same as c.235delC?
Yes, rs111033620 is the unique identifier (rsID) used in genetic databases for the specific mutation commonly referred to in medical literature as c.235delC.
Does having this variant mean I will be deaf?
Not necessarily. Because this condition is autosomal recessive, you would typically need to inherit two copies of the variant to be affected. Being a carrier (having one copy) generally does not cause hearing loss.
Why is this variant common in East Asian populations?
This is often due to a 'founder effect,' where the mutation was present in a small ancestral group that expanded over time. This leads to a higher frequency of the variant within that specific population compared to others.
Should I get tested for GJB2 variants?
Genetic testing is a personal decision often made in the context of family planning or if there is a family history of hearing loss. You should discuss the benefits and limitations of such testing with a genetic counselor.
Sources & further reading
Educational information only, last refreshed 9/24/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Also known as 35delG, this frameshift mutation is a major cause of autosomal recessive nonsyndromic sensorineural hearing loss.
Pathogenic nonsense variant (p.Trp24Ter) in GJB2, representing one of the major causative alleles for autosomal recessive non-syndromic hearing loss in Mediterranean and South Asian groups.
This variant is associated with autosomal recessive nonsyndromic hearing loss.
Missense variant (p.Arg127His) in the GJB2 gene. While often reported in individuals with hearing loss, it is frequently classified as benign or likely benign in clinical databases when found in isolation, as it is common in the general population.
A missense variant (c.109G>A, p.Val37Ile) in GJB2, often identified as a common pathogenic variant associated with mild to moderate autosomal recessive nonsyndromic hearing loss (DFNB1A).
Common East Asian frameshift mutation (c.235delC) causing severe truncation of Connexin 26, a major cause of autosomal recessive nonsyndromic hearing loss.