Usher syndrome - "a genetic disease causing deaf and blindness."
A simple definition. In essence, this disease slowly blinds you
by progressive retinis pigmentosa, as well as ruin your hearing
through congenital hearing loss. This particular disease can
only be inherited, and is uncommon becuase it is a recessive
trait. It can occur in an estimated 1 in 11,000 people.
"Usher
Syndrome" is not a name which best describes or reflects its
signs and symptoms. It was named this becuase of C.H. Usher, a
British ophthalmologist. He wrote about the disease when it was
unknown, and described cases in which there was a clear link
between congenital deafness and retinis pigmentosa. This was
long ago, and he was ahead of his time, as the paper was writtin
in 1914.
This condition has three seperate types; Usher Syndrome I, II
and III. I is the most unfair, as the child is born almost
completely deaf, and eyesight begins to fail after about age 10.
In type II, eyesight does not tend to degrade until later in
life, but the child is born hard of hearing. Type III syndrome
is the most common, wherein loss of sight and hearing occurs
much later in life.
The USH3A gene is responsible for creating a protien that is
essential in the development and upkeep of the retina and inner
ear. Usher syndrome type III is a result of a mutation whithin
this gene, however, the full explanation as to the protiens role
in vision and hearing loss, is yet to be discovered.
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