Ushers Syndrome

The Usher syndromes (USH) are a large group of inherited disorders which combine simultaneously both the hearing impairment and progressive loss of vision due to Retinitis Pigmentosa (RP). RP can result in the gradual loss of night vision and peripheral vision, resulting in "tunnel vision".

There are considered three types:

• Type 1 (USH1) is characterized by a congenital (present at birth), severe to profound and preverbal deafness, absent balance function and early onset of an night blindness and peripheral vision loss (typically by age 5 or 6 years and almost always before age 10 years.)
• Type II (USH2) has a milder (post-verbal) hearing loss, apparently present from birth, and a later onset (or detection) of an RP-like retinal degeneration (typically between ages 10-20 years). Balance functions are normal and stable, but the hearing impairment deteriorates very slowly, by some estimates an average of about 1 decibel (Db) per decade.
• Although still controversial, the existence of at least a third type (USH3), distinguished from USH2 by the rapid and progressive nature of its hearing loss, has been suggested. USH3 seems to account for about 40% of Usher syndrome patients from eastern Finland; there is good genetics evidence that the gene for USH3 is located on a different chromosome than the locations of USH1 and USH2.

Note: There may even be a rare Usher Syndrome Type IV, not yet well characterized.

Gradual loss of central vision.

All forms of RP and RP-related disorders, like the Usher syndromes, are genetic, which means caused by altered genes. In order to be effected, an individual must inherit one Usher gene from each parent. The likelihood of this happening is 1 in 4. If the individual inherits only 1 altered gene, that person would then be considered a "carrier" but there will be no symptoms.

There is no treatment available to date.