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GJB2 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

GJB2 gene

The GJB2 gene provides instructions for the connexin 26 protein, which is essential for hearing and the maintenance of healthy skin.

Normal Function

The GJB2 gene provides instructions for making a protein called gap junction beta 2, or connexin 26. This protein forms gap junctions that transport potassium ions and small molecules between cells. In the inner ear, specifically the cochlea, these channels are necessary to recycle potassium ions, which is a process required to convert sound waves into electrical nerve impulses. In the skin, connexin 26 is involved in the growth, maturation, and stability of the epidermis.

Health Conditions Related to Genetic Changes

Nonsyndromic hearing loss

Pathogenic variants in GJB2 are a leading cause of nonsyndromic hearing loss (DFNB1A). These "loss-of-function" variants disrupt the assembly or function of gap junctions in the inner ear, altering potassium ion availability and affecting the survival of cells necessary for hearing.

Syndromic conditions

Variants in GJB2 are also associated with several syndromes involving both hearing loss and skin abnormalities:

  • Bart-Pumphrey syndrome: Characterized by white nail discoloration, palmoplantar keratoderma, knuckle pads, and hearing loss.
  • Keratitis-ichthyosis-deafness (KID) syndrome: Involves inflammation of the cornea, dry scaly skin (ichthyosis), and deafness.
  • Hystrix-like ichthyosis with deafness (HID): Often categorized with KID syndrome; involves severe skin scaling and profound hearing loss.
  • Palmoplantar keratoderma with deafness: Involves thick skin on the palms and soles alongside hearing loss.
  • Vohwinkel syndrome: Characterized by hearing loss and the development of fibrous bands around fingers and toes that can lead to spontaneous amputation.

In many of these syndromic conditions, the altered protein creates "leaky" channels that impair cell health or interfere with the function of other gap junction proteins.

Other Names for This Gene

  • CX26
  • DFNA3
  • DFNB1
  • NSRD1

Frequently Asked Questions

Early intervention is critical for children with GJB2-related hearing loss. The primary goal is to provide auditory access to sound as soon as possible, typically through hearing aids or cochlear implants, depending on the severity of the loss. This should be paired with intensive speech and language therapy to help the child learn to process and produce speech. Parents are often encouraged to use visual cues, sign language, or cued speech alongside verbal communication to ensure the child does not experience language deprivation. Regular audiological monitoring is essential to adjust devices as the child grows and to ensure the implants or aids are functioning optimally.
GJB2-related hearing loss is typically non-progressive, meaning that once the hearing level is established, it usually does not get worse over time. This is a significant advantage compared to progressive genetic conditions where hearing loss deepens with age. However, the degree of loss can vary widely, from mild to profound. Because the condition is static, early surgical intervention, such as cochlear implantation, can be highly effective and provide stable long-term outcomes. Patients do not typically experience the fluctuating hearing levels seen in some autoimmune or infectious causes of deafness.
While many individuals with GJB2 variants have isolated hearing loss, some may develop skin conditions associated with syndromic forms like Bart-Pumphrey syndrome or Vohwinkel syndrome. Patients should monitor for thickening of the skin on the palms and soles (palmoplantar keratoderma), white discoloration of the nails, or the formation of fibrous bands around the fingers and toes. Management involves regular dermatological check-ups. For thickened skin, moisturizing and gentle exfoliation may help, while severe cases of fibrous bands may require surgical intervention to prevent constriction and potential tissue damage. Early detection of skin changes is key to preventing complications.
Yes, GJB2-related hearing loss is most commonly inherited in an autosomal recessive pattern. This means that an individual must inherit two copies of the pathogenic variant, one from each parent, to develop the condition. Parents who are carriers typically have normal hearing because they have one functional copy of the gene. If both parents are carriers, there is a 25% chance with each pregnancy that the child will have hearing loss, a 50% chance the child will be a carrier, and a 25% chance the child will not have the variant. Genetic counseling and carrier testing are recommended for couples with a family history of hearing loss to assess risks and discuss options such as prenatal diagnosis or preimplantation genetic testing.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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