Thinking about a White kitty with blue eyes.....

[mews2much]

My friend has 2 Cats with Blue Eyes and they are Deaf. My Friend is Deaf too. Her Cats do fine.

 

[yosemite]

Originally Posted by LDG

You're right. From a breeding perspective, the article is much too general. For laypeople, it discusses the statistical correlations in an understandable fashion.

According to UC Davis, the incidence of white cats with blue eyes and deafness is Waardenburg's syndrome: http://www.vetmed.ucdavis.edu/course...nburgssyndrome

Though of course not all sources of deafness are caused by Waardenburg's.

Using mice, researchers of Waardenburg's isolated a gene that is a cause of the Syndrome (in people and mice) as reported in Science News in 1992: http://findarticles.com/p/articles/m...41/ai_12121304

As you already pointed out, the issue is not that there are genes for blue eyes, white fur and deafness. The white fur and - more frequently - the blue eyes - are merely genes that are statistically correlated to the presence of the gene or genes that then cause the cat to become deaf, as it appears that, according to the Science News article "Melanocytes play in important role in the inner ear of mammals. They make up a tiny, dark stripe that winds through the cochlea, the spiral-shaped organ that contains the so-called hair cells that sense sound waves. By regulating the concentrations of charged potassium and sodium atoms in the special fluid within the cochlea, melanocytes allow the hair cells to generate electrical signals that convey sound to the brain. If these melanocytes fail to grow or move to their appropriate places in the developing embryo, Milunsky and Read assert, deafness and pigmentation anomalies could result."

However, Waardenburg's has three diffferent classifications and mutations in six different genes have been identified as causing it according to the genetics home reference discussion of Waardenburg's Syndrome at the National Institutes of Health: http://ghr.nlm.nih.gov/condition=waardenburgsyndrome

What research has been done with cats, and how this all plays out from a breeder's perspective, I have no idea.

But to correct my original statement, it appears that between 55% and 85% of white cats that have blue eyes are also deaf. (http://www.keoka.com/whtdeaf/index.htm) While the deafness is not caused by one gene, the tendency for developmental problems of the embryo that will cause congenital deafness exists in many white cats with blue eyes. If a cat is white and has bi-color eyes and of those is blue, it is highly likely that the cat is deaf in the ear that is on the same side of the head as the blue eye. It is hereditary, but how to breed out deafness in white cats with blue eyes has not yet been fully identified.

...and, of course, cats that are not white and do not have blue eyes can be born deaf, but the cause would not be Waardenburg's Syndrome per se.

Footnote: A mutation of the Pax-3 gene, which does cause deafness as Waardenburg's Syndrome in people, does not appear to be the cause of deafness in dalmations - and how it affects cats, I have not yet found any research.

Laurie

Wow - TMI for this dumb-bunny.

 

[sol]

Originally Posted by LDG

But to correct my original statement, it appears that between 55% and 85% of white cats that have blue eyes are also deaf. (http://www.keoka.com/whtdeaf/index.htm)

It's important to note that those numbers are extremely general and in most part based on random matings (i.e. domestic shorhairs/longhairs). Studies done on purebred white cats often show lower numbers than that.
I'm gonna try to find the magazine where the Swedish study on white Devon Rexes and Cornish Rexes were published.

So it definately matters if we're talking purebred cats or random mated cats.

I'm gonna check out some of the links, great work on collecting information!

 

[ldg]

Originally Posted by Sol

It's important to note that those numbers are extremely general and in most part based on random matings (i.e. domestic shorhairs/longhairs). Studies done on purebred white cats often show lower numbers than that.
I'm gonna try to find the magazine where the Swedish study on white Devon Rexes and Cornish Rexes were published.

So it definately matters if we're talking purebred cats or random mated cats.

I'm gonna check out some of the links, great work on collecting information!

I was just looking at it as the guardian of a white cat with light blue/green eyes that is deaf - although we believe her deafness is due to illness, not having been born that way because she can seem to hear certain frequencies (though it could just be senses vibrations at some frequencies).

Either way - I knew that many deaf cats with blue eyes were deaf, or that there was a high probability that they are - and deaf kitties make GREAT companions - so long as they are indoors only.

Of course, understanding the problem is a totally different ball of wax for a breeder.

...and I don't know how much digging you plan to do, but there's been a LOT of work done on mice re: Waardenburg's. There have also been a lot of studies subsequently done on a number of the genes that "cause" Wardenburg's. I didn't spend a lot of time on it, but apparently deafness is a problem with dalmations, because there's been a fair amount of gene research funded by a dalmation group. I found almost nothing on cat breeding, genetics, and hereditary tendencies that wasn't 10 years old or more (as relates to deafness or Waardenburg's - especially as regards breeding white cats and/or blue eyes into the gene pool). There was a paper published in 1971 by Bergsma & Brown specifically on hereditary traits of white cats with blue eyes and deafness - if you want to pay for it, it is available through Oxford Journal of Heredity. But the 1995 paper by the Keoka Maine Coon breeders points out a number of flaws in the research.

Happy to send along other links if you want them. Just PM me.

Laurie

 

[chrissyr]

Originally Posted by hammyandwaf

Ignoring is not in a kittys vocabulary at least not in my kitties vocab. lol

Not in my kitties vocabulary either. Ignore the cat talk, be prepared for the back-up action. LOL