The Usher syndromes (USH) comprise genetically-related disorders that bring about simultaneous hearing loss and vision loss (resulting from an eye condition called retinitis pigmentosa). Retinitis pigmentosa is the loss of night and peripheral vision, resulting in tunnel vision (seeing only straight ahead). Most people with Usher also have severe balance problems.
Types of Usher
There are three types of Usher (USH), all with similar symptoms. Different genes have been identified for each type. When an eye doctor looks at the retina in a patient with Usher, the optic nerve looks very pale, the blood vessels supplying nutrients to the retina are thin, and the doctor can see that there are characteristic spots and splotches of pigment called bone spicules.
- Type 1 Usher. At birth, the child is severely deaf with severe balancing problems. Before age 10 years old, the child may begin to develop vision problems. This genetic disorder has been identified frequently in today's Ashkenazi Jewish population. This type of Usher syndrome includes problems with the inner ear affecting balance that results in children being unable to sit or walk independently until later than usual.
- Type 2 Usher. At birth the child has moderate to serious deafness and normal capacity to balance. These children are assisted by a hearing aids. Retinitis pigmentosa isn't noticed until they are in their teens. Type 2 is thought to be the most common form of Usher syndrome, although the frequency is unknown. The vision problems of this type 2 tend to progress more slowly than those of type 1.
- Type 3 Usher. These children do not have hearing problems at birth and they have normal or almost normal balance. However hearing and vision deteriorate with time, usually by the teen years. Balance difficulties might develop later on. Hearing aids are usually needed by adulthood, and night blindness may start in early teens. Blind spots can develop and the person is often legally blind by mid-adulthood. The clinical diagnosis refers to a central visual acuity of 20/200 or less in the better eye, with the best possible correction and/or a visual field of 20 degrees or less. Type 3 Usher syndrome accounts for only a small percentage of all Usher syndrome cases in most populations. This 3rd type is prevalent in Finland.
Next: Nutrients, diet, & lifestyle for Usher syndromes.
Signs and Symptoms
- Profound deafness in both ears from birth
- Decreased night vision before age 10
- Balance problems from birth
- Moderate to severe hearing loss from birth
- Decreased night vision begins in late teens
- Balance typically remains normal
- At birth, children typically have normal hearing
- Near normal balance but problems can start to slowly develop over time
- Rate of decline in hearing and vision loss varies
- Vision and hearing loss often develop in adolescence
- Night blindness and the appearance of blind spots often develop in adolescence
- Legal blindness often occurs by midlife
Usher syndrome is inherited as an autosomal recessive trait, which means that the mutated gene is not located on either of the chromosomes (X or Y) that determine a person's sex. This means that both males and females can have the disorder and can pass it along to a child. Because it is recessive, both parents must have the mutation; two copies of the mutated gene are required. If someone has only one mutated gene, from one parent, they have the capacity to pass the trait on to a child but do not themselves exhibit any symptoms of the condition.
Some specific genes have been identified, but there may be more.
- Type 1 involves the genes: CDH23, MY07A, PCDH15, SANS, USH1C
- Type 2 involves: USH2A, VLGR1, WHRN
- Type 3 involves: USH3A
These genes are responsible for proper development of normal hearing, balance, vision, and function in the development and maintenance of fine hair-like cells in the inner ear that help transmit sound and motion signals to the brain. In the retina, these genes are also involved in determining the structure and function of the light-sensing cells called rods and cones.
There is no treatment available to date for any of the three types of Usher syndrome. It is important, however, to diagnose the condition early, so that early childhood communication and development skills may be learned before too much hearing or sight is lost. There is some future possibility of artificial retina implantation, and development of retina cells from stem cells.
Targeted supplementation may help slow down the progression of vision loss in type 2 and type 3. Antioxidants and nutrients1 may "hyper-nourish" the retina by supporting the retinal cells that are lost due to retinitis pigmentosa (particularly the rod photoreceptor cells that enable us to see at night, in low light, and provide peripheral vision).2 Certain herbs have been shown to help support hearing as well.
Early Communication Skills. In the case of type 1 Usher, work with your child's doctor to determine the best communication method as
soon as possible. This is important because in very early life your child's brain is very receptive to learning language
skills. If the child begins this process well before sight is lost, he/she will have the best chance of living a normal life.
Management. To help manage and possibly slow the progress of the condition, these vision support tips are important.
- Certain nutrients such as lutein, zeaxanthin,3, 4, 5 vinpocetine, l-lysine, a number of vitamins such as vitamin A & E,6 & enzymes, and fish oil7 may help slow down loss of vision.
- See all retinal support vitamins and supplements
- Some research indicates that daily use of microcurrent stimulation8 may help preserve vision as well.
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Next: Nutrients, diet, & lifestyle for Usher syndromes.
1. Sofi, F., Sodi, A., Franco, F., Murro, V., Biagini, D., et al. (2016). Dietary profile of patients with Stargardt's disease and Retinitis Pigmentosa: is there a role for a nutritional approach? BMC Ophthalmol, Jan 22;16:13.
2. Moukarzel, A.A., Bejjani, R.A., Fares, F.N. (2009). Xanthophylls and eye health of infants and adults. J Med Liban, Oct-Dec;57(4):261-7.
3. Krinsky, N.I., Landrum, J.T., Bone, R.A. (2003). Biologic mechanisms of the protective role of lutein and zeaxanthin in the eye. Annu Rev Nutr, 23:171-201.
4. Bahrami, H., Melia, M., Dagnelie, G. (2006). Lutein supplementation in retinitis pigmentosa: PC-based vision assessment in a randomized double-masked placebo-controlled clinical trial [NCT00029289]. BMC Ophthalmol, Jun 7;6:23.
5. Berson, E.L., Rosner, B., Sandberg, M.A., Weigel-DiFranco, C., Brockhurst, R.J., et al. (2010). Clinical Trial of Lutein in Patients With Retinitis Pigmentosa Receiving Vitamin A. Arch Ophthalmol, Apr;128(4):403-11.
6. Berson, E.L., Rosner, B., Sandberg, M.A., Hayes, K.C., Nicholson, B.W., et al. (1993). A randomized trial of vitamin A and vitamin E supplementation for retinitis pigmentosa. Arch Ophthalmol, Jun;111(6):761-72.
7. Massachusetts Eye and Ear. New Findings Lead to Revised Therapeutic Regimen to Slow RP. Retrieved Dec 04 2017 from http://www.masseyeandear.org/for-patients/patient-guide/patient-education/diseases-and-conditions/rp-and-supplements
8. Halloran, G. (1997). Bioelectrical Stimulation in an Integrated Treatment for Macular Degeneration, RP, Glaucoma, CMV-Retinitis, and Diabetic Retinopathy; Fourth Annual Symposium on Biological Circuits, Oct. Mankato University, MN.
See research on retinitis pigmentosa.