Download Usher`s Syndrome

yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

Artificial gene synthesis wikipedia , lookup

Saethre–Chotzen syndrome wikipedia , lookup

Gene therapy of the human retina wikipedia , lookup

Microevolution wikipedia , lookup

Medical genetics wikipedia , lookup

Gene expression profiling wikipedia , lookup

Designer baby wikipedia , lookup

Genomic imprinting wikipedia , lookup

Genome (book) wikipedia , lookup

DiGeorge syndrome wikipedia , lookup

Williams syndrome wikipedia , lookup

Down syndrome wikipedia , lookup

Author: Jack Slemenda
Converse College, SC
Date submitted to – March 20, 2008
To contact the author for permission to use this
PowerPoint, please e-mail:
[email protected]
To use this PowerPoint presentation in its
entirety, please give credit to the author.
Usher’s Syndrome
Jack Slemenda
Converse College
Usher’s Syndrome is an inherited
condition that causes 1) a serious
hearing loss that is usually present at
birth or shortly thereafter and 2)
progressive vision loss caused by
retinitis pigmentosa (RP).
RP is a group of inherited diseases
that cause night-blindness and
peripheral (side) vision loss through
the progressive degeneration of the
retina, the light-sensitive tissue at the
back of the eye that is crucial for
Who is affected by Usher’s
Approximately 3-6 percent of all deaf
children and perhaps another 3-6
percent of hard-of-hearing children
have Usher Syndrome. In developed
countries such as the United States,
about 4 babies in every 100,000 births
have Usher’s Syndrome.
What causes Usher’s
Usher’s Syndrome is inherited or passed
from parents to their children through
Some genes specify traits such as hair
color. Other genes are involved in the
development of body parts, such as the
ear. Still others determine how parts of the
body work. Each person inherits two copies
of each gene, one from each parent.
Additional Causes of Usher’s
Genes for Usher’s Syndrome are
autosomal recessive, a term meaning that
1) Usher genes are located on
chromosomes other than the sex
chromosomes, and 2) both parents must
contribute the mutated gene to the child
before the disorder is seen.
A number of different genes have been
found to cause the various types of Usher’s
How is Usher’s Syndrome diagnosed?
Since Usher’s Syndrome involves
both hearing and visual symptoms;
testing is performed on both.
Visual function tests: visual fields
and electroretinogram (ERG)
A retinal examination
Hearing tests
Balance tests for all patients age ten
years and older
What are the types of Usher’s
Type 1 (USH1)
Type 2 (USH2)
Type 3 (USH3)
Together, they account for
approximately 90-95 percent of all
cases of children who have Usher’s
Characteristics of the three types of
Usher’s Syndrome?
Type 1
Profoundly deaf from birth
Have severe balance problems. Because of the balance
problems, children with USH1 are slow to sit without support
and rarely learn to walk before they are 18 months old.
Little or no benefit from hearing aids. Most use sign
language as their primary means of communication.
Usually begin to develop vision problems by the time they
are ten. Visual problems most often begin with difficulty
seeing at night, but tend to progress rapidly until the
individual is completely blind.
Characteristics of Usher’s Syndrome
Type 2
Born with moderate to severe hearing
impairment and normal balance.
Use speech to communicate.
Visual problems progress more slowly.
Characterized by blind spots that begin
to appear shortly after the teenage
When an individual's vision deteriorates
to blindness, his or her ability to speech
read is lost.
Characteristics of Usher’s Syndrome
Type 3
Normal hearing and normal to near-normal balance.
Hearing worsens over time Children develop
noticeable hearing problems by their teenage years
and usually become deaf by mid- to late adulthood.
Night blindness usually begins sometime during
puberty. Blind spots appear by the late teenage years
to early adulthood. By mid-adulthood, the individual is
usually blind.
How is Usher’s Syndrome treated?
There is no cure for Usher’s Syndrome.
The best treatment: early identification (by a Genetics
Doctor) in order to begin educational programs. The
nature of these educational programs will depend on
the severity of the hearing and vision impairments as
well as the age and abilities of the individual. Special
training needs to incorporate the family, as well.
Access to technology :hearing aids, assistive listening
devices, or cochlear implants; orientation/ mobility
training; and communication services and
independent-living training that may include Braille
instruction, low-vision services, or auditory training.
Communication services and independent-living
training that may include Braille instruction, low-vision
services, or auditory training.
Latest research findings
June 12, 1998, issue of the journal Science, by Dr.
William J. Kimberling, an investigator supported by
the National Institute on Deafness and Other
Communication Disorders (NIDCD).
The scientists described three different mutations
in a gene called USIIa. This gene was previously
mapped to a location on chromosome 1 and is
associated with the syndrome.
In April 2003, NIDCD researchers, along with their
research collaborators from universities in New
York, N.Y., and Tel Aviv, Israel, pinpointed a
mutation, named R245X, of the PCDH15 gene that
accounts for a large percentage of USH1 cases in
today's Ashkenazi Jewish population.
Usher’s Syndrome is rare in the general
population (3 per 100,000). However, two to 5
percent of the genetic deaf population have the
disease. This inherited condition is the cause
of more than half of all deaf-blindness in adults.
Students need to be informed that they have
Usher’s and also of the disabling conditions.
Students visual field and dark adaptation
abilities deteriorate so that they will need
additional assistance during the evening hour
Provisions for those with
Usher’s Syndrome
Family counseling
Medical and
Educational diagnoses
Itinerant home
Teacher training
Instruction: includes
the use of other
senses; augmentative
devices; enlarged
books, symbols and
tactile objects..
Dorothy Stiefel’s book called The Madness
of Ushers Syndrome: Copying with Vision
and Hearing Loss/Usher’s Syndrome Type
American Association of the Deaf-Blind
814 Thayer Avenue, Suite 302
Silver Spring, MD, 20910
Voice: (301) 495-4403
TTY: (301) 495-4402
Fax: (301) 495-4404
E-mail: [email protected]
Additional Resources
Better Hearing Institute (BHI)
515 King Street, Suite 420
Alexandria, VA, 22314
Toll-free Voice: (800) EAR-WELL (327-9355)
Helen Keller National Center for Deaf-Blind
Youths and Adults (HKNC)
141 Middle Neck Road
Sands Point, NY, 11050
Voice: (516) 944-8900
TTY: (516) 944-8637
Scheetz, Nanci A., (2001)Orientation to
Deafness 2nd Edition . Library of Congress
National Institute on Deafness and Other
Communication Disorders
National Institutes of Health
31 Center Drive, MSC 2320
Bethesda, MD USA 20892-2320
E-mail: [email protected]