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Eye Condition Fact Sheet
Condition
Usher Syndrome
Description
Usher syndrome is an inherited condition which results in hearing loss
and a progressive loss of vision from Retinitis pigmentosa (RP) a
degenerative condition of the retina, and usually appears during
adolescence or early adulthood. RP can occur without hearing loss. The
condition is named after a British ophthalmologist, C.H. Usher, who in
a paper in 1914 described several cases in which the link between
congenital deafness and RP was stressed. Other names for Usher
syndrome include Hallgren syndrome, Usher-Hallgren syndrome, rpdysacusis syndrome and dystrophia retinae dysacusis syndrome.
Photograph of the retina of a patient with Usher syndrome (left) compared to a normal
retina (right). The optic nerve (arrow) looks very pale, the vessels (stars) are very thin
and there is characteristic pigment, called bone spicules (double arrows).
Parts of visual system affected/Effects on the conditions of visual
system
There are at least three different forms of Usher syndrome.
Usher syndrome type 1 (USH1)
People with Usher syndrome type 1 (USH1) are born completely
deaf and experience problems with balance.
Usher syndrome type 2 (USH2)
In Usher syndrome type 2 (USH2), newborns have moderate to
severe hearing impairment.
A rarer third type of Usher syndrome (USH3) was documented in 1995.
Children with USH3 are usually born with good or only mild
impairment of hearing. Their hearing and vision loss is
progressive, starting around puberty. Balance may be affected.
Treatments
Currently, there is no cure for Usher syndrome. The best treatment
involves early identification so that educational programs can begin as
soon as possible. Researchers found that vitamin A palmitate can slow
retinal degeneration in some people with RP and Usher syndrome type
2.
Is condition congenital, adventitious, progressive or stable?
Usher is transmitted genetically by an autosomal recessive gene. To
produce a child with Usher both parents must carry the recessive gene.
Autosomal implies that the gene is not sex linked and so both males and
females are equally affected by the condition. In recessive inheritance
both parents carry the gene, but are not aware that they are carriers
until the condition is diagnosed in their children. The child with Usher
syndrome has two recessive genes for the trait and will transmit these
genes to their offspring.
Anticipated functional implications of the condition
This syndrome is characterized by deafness and a gradual vision loss.
The hearing loss is associated with a defective inner ear, whereas the
vision loss is associated with retinitis pigmentosa (rp), a degeneration of
the retinal cells. Special tests such as electronystagmography (ENG) to
detect balance problems and electroretinography (ERG) to detect
retinitis pigmentosa help detect Usher syndrome early. Furthermore,
symptoms of Usher Syndrome may vary on an individual basis for each
patient. Only your doctor can provide adequate diagnosis of symptoms
and whether they are indeed symptoms of Usher Syndrome.
References
http://www.blindness.org/content.asp?id=47
http://www.nidcd.nih.gov/health/hearing/usher.asp
http://www.deafblind.com/usher.html
http://www.medicinenet.com/usher_syndrome/page3.htm
http://www.cureresearch.com/u/usher_syndrome/symptoms.htm