Albinism in cats and, the partial albinism associated Siamese, Tonkinese, Burmese and Thai breeds were key to identifying and understanding several mutations in a gene cats and humans have that impact pigment production and indicated in brain function and vision. Complete albinism, Ca in cats and partial albinism expressions of Color point, Sepia, and Mocha are all caused by variants or mutations in the TYR gene, Tyrosinase.
Feline Albinism in the Donskoy breed is a rare example in cats of albinism associated with pink eyes. In this breed that also features hairlessness, the variant is related to the human condition known as Hermansky–Pudlak Syndrome.
A form of albinism in cats associated with blue eyes is not associated with any specific breed. This form of albinism occurs with photophobia, fear, or avoidance of light. The same mutation has been identified in people, mice, and cats.
Each of the different known variants causes a different limitation to pigment, and in the case of Siamese (Cs) and Burmese (Cb), cats unique heat sensitive version that is unknown in any other mammal. In people variants in TYR occur in lighter skinned people of European, Middle Eastern and Southern Africa. Siamese, Burmese and Tonkinese breeds were essential in understanding they traits when they occur as a homozygote or heterozygote.
Mink, the coloration most associated with the Tonkinese breed is NOT caused by a unique gene or variant. There is no unique gene for mink coloration. Instead, Mink is caused when a cat inherits one copy of Cs and one copy of Cb, creating a partial albinism of intermediate expression between a cat with two copies of Cs/Cs and Cb/Cb.
The Mocha, Cm, was identified in cats imported from Thailand or had recently Thai heritage and appears to not to be thermodynamic. The color creates a light chocolate appearance and is characterized as co-dominant with the Burmese variant TYR mutation.
New research indicates changes in the TYR gene may also be indicative of neurodegenerative diseases such as Alzheimer’s Disease in humans.
