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 one 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.