Just like people and all other creatures great and small, the normal genetic sequencing and physical appearance of the cat will occasionally throw up an anomaly or mutation that causes a departure from the norm in terms of some aspect of the physical appearance of the cat in question.
In the wild, these genetic anomalies would usually fail to be bred in great numbers into the subsequent offspring of cats carrying the genetic mutation, as the anomalous gene is often recessive. Even in the case of dominant genes, sometimes when the gene is present in a pair (such as if both parent cats carry the gene) this can result in unviable embryos or sterility in subsequent offspring.
However, many naturally occurring genetic anomalies that have led to a certain unusual physical trait in the cat have proven to be appealing and desirable to some cat lovers and breeders. Human intervention into the natural breeding process of cats has perpetuated the presence of many different genetic anomalies and even established a variety of breeds for which the anomaly itself is the signature trait.
Some of the most common recognised physical mutations, plus details of the breeds that contain them, are detailed below.
The normal feline ear is erect and gently pointed, but various different ear mutations are also possible and seen across some breeds of cat.
Polydactyly is one of the most common paw deviances from the norm in cats, and leads the cats to be born with extra toes. Many different genes are thought to contribute to this anomaly, which is not harmful or problematic for the cats in question. “Polydactyl” is the term used to refer to cats of this type, although it is not a breed in and of itself, and the condition can occur in any breed of cat.
While both pedigree cats and non pedigree cats come in a variety of sizes and some breeds are generally naturally larger or smaller than others, cats as a general rule follow a reasonably stable pattern of shape and size.
These mini-Persians are usually referred to as teacup Persians or toy Persians, as are other smaller-than-normal Persian cats that may or may not be related to Treker, including Persian cats that have been deliberately bred for a small size by other means.
Many of the mutations and anomalies mentioned above would naturally die out and not perpetrate themselves in long lines of subsequent offspring without human intervention. Even among the gene mutations that have bee found to have a potential adverse affect on the health and wellness of cats that carry the gene, human intervention into breeding programmes has perpetuated their presence and raised the popularity and desirability of cats of that type.
Understandably, there is a strong moral argument to be made against the case for doing this, and the GCCF (Governing Council of the Cat Fancy) refuses to recognise some breeds of cat that are bred for a specific mutation, such as in the case of the Munchkin cat and the Scottish Fold.
The Munchkin cat is rejected as a breed by the GCCF as the shortened limbs of the breed are considered to be anomalous and a significant and unnecessary deviation from the natural conformation of the cat, that may cause problems with mobility and survival in the wild.
The GCCF rejects the Scottish Fold cat as a viable breed, because the gene anomaly that causes the folded ears is also associated with skeletal abnormalities and significant stiffness and difficulty with mobility as the cats of the breed age.