A “rex mutation” in cats refers to a naturally occurring genetic variation that primarily impacts the feline coat, resulting in a distinctive soft, curly, or wavy fur texture. This genetic change alters the structure of individual hair shafts, creating a unique appearance and feel often compared to plush fabrics. Cats with this mutation exhibit unique physical traits.
The Genetic Basis of Rex Coats
The curly coat of rex cats stems from spontaneous genetic mutations. These mutations affect the keratin structure within the hair shafts. For instance, the Devon Rex breed’s curly coat is linked to mutations in the KRT71 gene, which influences keratin 71, a protein involved in hair fiber formation.
In contrast, the Cornish Rex’s coat is caused by a distinct mutation in the LPAR6 gene. This gene encodes a G protein-coupled receptor involved in maintaining the hair shaft’s structural integrity. These mutations are recessive, meaning a cat must inherit two copies of the mutated gene, one from each parent, to display the curly coat. Different rex breeds have different genetic causes for their curly coats, meaning a Cornish Rex and a Devon Rex are not genetically related through their “rex” trait.
Unique Physical Characteristics
The most noticeable physical characteristic resulting from a rex mutation is the coat itself, which can range from fine and slightly wavy to tightly curled or kinked. Unlike most cats with three distinct hair layers—guard hairs, awn hairs, and down hairs—rex cats often have a reduced number or complete absence of guard and awn hairs. For example, the Cornish Rex possesses only the soft, short down hair, giving its coat a silky, rippled appearance.
Beyond the coat, rex cats display other unique features. Their whiskers, typically straight in other breeds, are frequently curly or even absent. Some breeds also exhibit distinct facial structures, such as the Devon Rex’s large, wide-set ears and “pixie-like” appearance, or the Cornish Rex’s wedge-shaped head and large, mobile ears.
Popular Rex Cat Breeds
Several well-known cat breeds exhibit the rex mutation, each with unique origins and characteristics.
Cornish Rex
Originating from Cornwall, England, in 1950, the Cornish Rex is known for its lean, athletic build and a coat curled or rippled across its entire body, including its whiskers and eyebrows. Its coat is exceptionally fine, soft, and lacks guard hairs, often compared to velvet.
Devon Rex
Discovered in Devon, England, in the late 1950s, the Devon Rex possesses a short, dense, soft coat that curls inwards, creating a waved or rippled effect, particularly on the back. This breed is recognized for its “pixie-like” head shape, large eyes, and oversized, wide-set ears. Cross-breeding a Devon Rex with a Cornish Rex results in straight-coated kittens.
Selkirk Rex
The Selkirk Rex, which originated in Montana, USA, in 1987, is distinct for its thick, plush, and loosely curled coat, setting it apart from sparser rex breeds. This breed can have both short-haired and long-haired varieties, with all three hair types exhibiting a gentle curl.
LaPerm
The LaPerm, discovered in Oregon in the early 1980s, is known for its soft, springy curls and ringlets that can cover the entire body or appear in patches. Some kittens are even born bald before their curls develop.
Living with a Rex Cat: Care and Health
Owning a rex cat involves specific considerations due to their unique coat. Grooming needs are generally minimal, as their short, often single-layered coats do not mat easily and shed less than other breeds. However, excessive brushing can damage their delicate hair, so gentle methods like hand stroking or wiping with a chamois are recommended to distribute natural oils.
Rex cats are sensitive to temperature changes because their sparse fur provides less insulation. They often seek warm places, such as laps or under lamps, and are best suited for indoor living to protect them from cold or wet weather. Their exposed skin can also be sensitive to sunburn and may require occasional cleaning to prevent oil buildup. While generally healthy, some rex breeds may have predispositions to certain conditions; for example, Devon Rexes can be prone to patellar luxation and a muscle disorder known as Devon Rex myopathy. Regular veterinary check-ups are important for early detection and management of any potential health issues.