 The white spotting factor is the variable expression of the piebald gene that varies from the minimal degree (1), as in the blue-eyed cats with white tip on the tail to the maximal degree (8–9) that results in a Van-patterned cat, as in Van cats, when coloured marks occupy at most 20% of the white background, but the white background in the breed covers about 80% of the body.Breeding two cats together with the same level of white spotting will produce cats with a similar degree of spotting.Van-patterned Turkish Vans are not prone to deafness, because their phenotype is associated with the van pattern (Sv) semi-dominant gene.