Genetics

Abbreviation	Meaning	Dominance	Possible combinations	Phenotype
A	Agouti	dominant	AA Aa	coat colour with agouti pattern with tabby pattern
a	non agouti	recessive	aa	coat colour without agouti pattern without tabby pattern
D	Dense - non diluted	dominant	DD Dd	non diluted coat colours are black and red
d	diluted	recessive	dd	diluted coat colours: black gets blue, red gets cream
I	Inhibitor	dominant	II Ii	suppresses pigmentation of the hairs, colour only partly present on the hair shaft, coat with silver white ground
i	non silver	recessive	ii	coat colour without silver
O	Orange	dominant Note: The O gene is linked to the X gene - this is called sex linked. Gene O is also a mimic gene, each colour is turned to red/orange.	OO	those cats are red females
			OY	those cats are red males
			Oo	those cats are females with a tortie shell coat, the coat colour is patched with red/cream patches
o	non orange	recessive	oo	females with non orange coat colour
			oY	males with non orange coat colour
S	Piebald spotting	dominant Note: This gene is said to be inherited with incomplete dominance. The normal ratio of 3:1 is turned to 2:1:1	SS	Van The cat has only colour on its tail and some patches on the head, sometimes few smaller colour patches on the body. Note: In some federations these cats are called Harlequins.
			Ss	Harlequin, Bicolour White colour can be mostly found on the belly, on the head, on the legs, the rest of the coat is coloured.
s	non white	recessive	ss	coat colour is without white
Ta	tabby ticked	dominant over tabby spotted/mackerel	Ta Ta	absence of stripes in the coat
			Ta Mc Ta mc	faint and fine stripes on the legs, in the face and on the tail.
Sp	tabby spotted	dominant over tabby mackerel	SpSp Spsp	the coat shows a spotted pattern*)
Mc	tabby mackerel	dominant over tabby blotched	McMc Mcmc	the coat shows a mackerel pattern This is the normal wild form of the tabby pattern.
mc	tabby blotched	recessive	mcmc	the coat shows a blotched pattern.
W	dominant White	dominant Note: Gene W is called a mimic gene, it covers all colours and patterns.	WW Ww	the whole coat is white The eye colour can be: orange, blue, odd eyed (one eye blue/green, the other orange) or green
w	non white	recessive	ww	the coat is coloured with no white

*) Note: some say there is no special gene for Spotted existent. One hypothesis says that the Spotting is derived from the mackerel pattern. That seems to be true if you look on the spotted cats commonly known, like the European Spotted, British Spotted or Oriental Spotted, and it seems to be true when you think about the Egyptian Mau.  The coat between the spotting pattern is ticked. Also the spots themselves are ticked. On this breed you can see the incomplete dominance of the gene Ta, as the Ocicat is ticked and at the same time shows spots. There is also another theory that a special group of genes (not a single gene, but a group) influences the way how the spots are arranged, more following a mackerel pattern or more following a blotched pattern.