These anomalies occur only with the dominant white gene, and even some cats with that dominant gene are exceptions if they are born with even small patches of color other than white. (thesprucepets.com)
Unlike the Black German Shepherd, however, whose true color is solid black, the recessive white gene acts as a mask, blocking the dog's true color and pattern and causing it to appear white. (animalso.com)
They have the Dominant White gene which can affect the way the inner ear develops. (messybeast.com)