Usher Syndrome

What is Usher Syndrome?

Usher syndrome is a genetic disorder which is characterized by both a sensorinueral hearing loss as well as the gradual loss of vision due to Retinitis Pigmentosa (RP). RP causes an individual’s vision to deteriorate over time typically resulting in night-blindness and a loss of peripheral vision (tunnel vision). As RP progresses, an individual’s field of vision continues to narrow until only the ability to see straight ahead remains.

Usher syndrome is a genetically transmitted from parent to child in a recessive manner, which means that an affected individual must inherit one copy of a non-functioning gene from each parent. Carriers, who only have one copy of the non-functioning gene and one normal gene, do not manifest any of the signs of the syndrome but have a 1 in 2 chance of passing the defective gene on to their own offspring (who would than also be carriers only), and a 1 in 4 chance of having an affected child if the other parent is also a carrier. Because individuals with Usher Syndrome will typically lose some or all of their vision, it is essential that their hearing loss be aggressively treated so that they can rely on their sense of hearing to guide them as their vision fails.

There are three distinct types of Usher syndrome which are detectible by blood test.

  • Individuals with Type 1 Usher Syndrome typically have a congenital severe-to-profound sensorineural hearing loss and severe vestibular (balance) problems. Because of the severity of the hearing loss, these individuals generally do not benefit from hearing aids but can be evaluated for cochlear implantation. Because of the balance problems associated with USH1, children with this disorder are slow to sit without assistance and typically do not walk independently before they are 18 months old. Vision problems generally begin to develop in early childhood and almost always by the time the child reaches the age of ten. Vision will continue to deteriorate until the individual is completely blind.
  • Individuals with Type 2 Usher Syndrome typically have a congenital moderate-to-severe sensorineural hearing loss and normal balance. Although the severity of the hearing loss is variable, some of these individuals will initially benefit from hearing aids. Individuals who do not benefit from hearing aids may also be considered for cochlear implantation. The visual problems associated with Type 2 Usher Syndrome tend to progress more slowly than with Type 1, with the onset of retinitis pigmentosa not apparent until the teen or early adult years.
  • Individuals with Type 3 Usher Syndrome have normal hearing at birth. Although most individuals with this type of Usher Syndrome initially have normal to near-normal balance, some may develop balance problems in later ears. Both hearing and vision will progressively deteriorate over time, however, the rate of decline is variable on a case-by-case basis. Typically, an individual with Type 3 Usher Syndrome will develop some level of hearing loss by the teen years, and will generally require some form of hearing devices by mid-to-late adulthood. Night blindness usually begins sometime during puberty with blind spots appearing by early adulthood and by mid-adulthood the individual may be legally blind.

What genes are involved in Usher Syndrome?

The genes that are responsible for Usher syndrome are:

  • Type 1 Usher syndrome: MY07A, USH1C, CDH23, PCDH15, SANS
  • Type 2 Usher syndrome: USH2A, VLGR1, WHRN
  • Type 3 Usher syndrome: USH3A

What is the Treatment for Usher Syndrome?

A specialized interdisciplinary team of professionals is necessary to treat all of the issues associated with Usher syndrome. This group of individuals should include an Otologist or Otolaryngologist, an Opthamalogist, audiologists, speech-language pathologists, a clinical geneticist and a genetic counselor. All of these individuals should have extensive experience in pediatrics.

The California Ear Institute is a leading global center for otological, otolaryngological and audiological treatment. Dr. Joseph Roberson and Dr. Katrina Stidham, both board certified neurotologists, have performed thousands of successful hearing related surgeries on children and adults, including many whose hearing impairment is due to Usher Syndrome.

What are the consequences of avoiding treatment?

If it is the desire of the family for their child to hear and speak as normally as possible, it is necessary to seek medical evaluation as soon as possible after birth of a child who is referred by their newborn hearing screening program for additional testing, regardless of whether or not Usher Syndrome is suspected to be the source of the hearing loss. Delays in treatment for profound sensorineural hearing loss will result in the inability for the patient to develop normal spoken speech and language skills. Additionally, candidacy for cochlear implantation, currently the only medical treatment available for the treatment of profound sensorineural hearing loss, cannot be established without a comprehensive medical examination. Avoiding medical evaluation for Usher syndrome or any other hearing impairment related condition is not recommended.

Additional Notes

Patients searching the internet for information about Usher Syndrome or any other medical issue should know when reading about individual case histories, that generally it is the patients with the most severe symptoms who either post their own experiences or are included in medical review journals. As a result, it is easy to become overly alarmed and assume the worst. Patients should keep this in mind as they explore the available resources, and look for sources that are certified by HON or other reputable health reviewing organizations. As with all medical conditions, prompt treatment by experienced medical personnel give the best chance for a positive outcome.

Conclusion

Usher Syndrome diagnosis and treatment requires a comprehensive medical examination and specialty care from an Otologist, who is an otolaryngologist (ENT) who has undergone two additional years of training and specializes in issues related to the nerves of hearing only. With appropriate medical treatment and therapy, individuals with Usher Syndrome will be able hear.

Click here to make an appointment with the California Ear Institute to consult with one of our board certified otologists regarding your condition.

Additional Reading