The Devon Rex is a cat you are unlikely to mistake for anything else: enormous low-set ears, wide-spaced eyes, a short curly coat and a face that has earned the breed the nicknames “elf”, “pixie” and “monkey in a cat suit”. This is a cat that lives not beside its human but literally on them — on the shoulders, under the comforter, up a sweater sleeve. Coat care is minimal, which is not the same as trouble-free: the Devon has its own set of skin quirks, its own compulsory blood test before mating, and its own hereditary disease with a ready-made DNA test. For more on cat breeds, visit Tvaryny.
And straight away, the thing the internet gets wrong about the Devon Rex more often than anything else. There are several curly-coated cat breeds, and almost every source says each one has “its own mutation”. The real picture is different and more interesting: the Devon Rex is not related to the Cornish Rex — the genes are different; whereas the Devon Rex and the Sphynx are two versions of one and the same gene. Nearly everything else follows from that single fact: why a Devon × Cornish cross produces straight-coated kittens, why one hereditary disease turns up in Devons and Sphynxes and nowhere else, and why the Devon’s coat is uneven rather than simply “curly”.
Devon Rex: a brief breed overview
Devon Rex: a brief breed overview · 14
| Characteristic | Description |
|---|---|
| Origin | Buckfastleigh, county of Devon, United Kingdom |
| Founder of the breed | The cat Kirlee, litter of 1959 |
| Curl gene | KRT71, allele re, recessive |
| Recognition | GCCF — 1967; CFA — registration 1979, championship status 1983; TICA — 1979 |
| Lifespan | 12–16 years |
| Height at the shoulder | 25–30 cm |
| Weight | Females 2.5–3.5 kg; males 3–4.5 kg |
| Temperament | Very affectionate, playful, intelligent, inquisitive, energetic; needs attention |
| Grooming | Minimal and pointedly gentle; regular ear cleaning and attention to the skin |
| Activity | High |
| Vocalization | Moderate (a quiet voice) |
| Compatibility with children | Very good |
| Compatibility with other animals | Good (with proper socialization) |
| Checks to require from the breeder | COLQ DNA test (Devon Rex myopathy / CMS) and blood type of both parents |
Three curly cats: why the Devon is no relative of the Cornish
In the middle of the twentieth century several curly-coated cats turned up in England within a few years of each other. The natural assumption was that this was one and the same mutation resurfacing here and there. There was only one way to test it at the time — mate the carriers and look at the kittens. If the mutation is a single one, every kitten is born curly. If the mutations are different, each covers the other’s fault and the kittens are born with straight coats.
The experiment that created the breed
Kirlee, the curly tom from Devonshire, was mated to females descended from Kallibunker, the founder of the Cornish Rex in neighboring Cornwall. Every kitten was born with a straight coat. That was the answer: Kirlee carried a different mutation. The geneticist Roy Robinson described it in 1969 in the journal Genetica as “a third rex mutation in the cat” — hence the old labels that still circulate in reference books: “gene I” (Cornish) and “gene II” (Devon).
Note the logic: straight-coated kittens were not the failure of the experiment, they were its result. It is precisely because the cross “went wrong” that the Devon Rex exists as a breed of its own rather than as a line inside the Cornish Rex.
What turned up once DNA could be read
Forty years later both mutations were identified by name, and the picture was not quite what the popular breed profiles describe.
- Devon Rex — the KRT71 gene. In 2010 the group led by Leslie Lyons (UC Davis) described in Mammalian Genome a complex rearrangement in this gene: an 81-base-pair deletion with insertions that disrupts splicing. The allele was named re; inheritance is recessive, so a curly Devon carries two copies.
- Cornish Rex — the LPAR6 gene. It was found in 2013, again by the Lyons team, in a paper published in PLOS ONE: a four-base-pair deletion in exon 5 that truncates the protein early. In the breed it is fully fixed.
- German Rex — the same LPAR6 as the Cornish. This is probably the single biggest correction to the usual talk of “three different rex genes”. The very same deletion was found in German Rexes; in that small breed it is not fixed but still segregating. So there are three curly breeds — but only two genes.
KRT71 and LPAR6 are entirely unrelated molecules. LPAR6 is a cell-surface receptor without which the hair shaft loses its structural integrity (in humans, faults in the same gene produce woolly hair). KRT71 is a type II keratin that builds the inner root sheath of the follicle: the Henle and Huxley layers and the cuticle of that sheath. In plain terms, it is the mold the hair is cast in. Damage the mold and the hair comes out distorted whatever it is made of.
Continue the census and KRT71 turns out to be the great “curly” gene of cats generally. Besides the Devon it also houses the Selkirk Rex mutation: the splice variant c.445–1G>C described in 2013 in Scientific Reports, with incomplete dominance — one copy is already enough to make the coat curl. The tally: four curly or hairless breeds account for two genes, with three variants of KRT71 (Sphynx, Devon, Selkirk) and a single LPAR6 (Cornish and German).
Devon and Sphynx: two steps of the same gene
This next point barely appears in breed profiles, although it explains a great deal. The same 2010 work showed that the Sphynx’s hairlessness is also a fault in KRT71, merely a different one: a point substitution affecting the same splicing mechanism. It was labeled hr. The result is an allelic series of three versions of one gene:
KRT71+ (normal coat) > KRT71hr (Sphynx) > KRT71re (Devon)
Read it like this: the normal coat dominates both faults, and the Sphynx’s hairlessness dominates the Devon’s curl. Every Devon Rex examined was homozygous for re, while many of the Sphynxes proved to be either homozygous for hr or compound heterozygous — carrying the “sphynx” and the “devon” allele at once.
This is not an abstraction but a working breeding rule — and the federations have settled it in opposite directions, which is telling. With the CFA, the Sphynx still lists the Devon Rex among its permitted outcrosses, with the proviso that Sphynxes born on or after 31 December 2033 may have only Sphynx parents. The British GCCF states the opposite, and bluntly, in its Devon Rex breeding policy: no cat with Sphynx ancestry should be introduced into the Devon Rex breed, because selection for hairlessness runs against the coat-quality requirements of the rex breeds; offspring of Sphynx × Devon matings go onto the reference register, do not count as variants and are not used in Devon breeding.
Traffic is therefore permitted in one direction only: the Devon may widen the Sphynx gene pool, not the other way round. Decades of such matings mean a shared gene pool — and therefore shared hereditary disease. In the health section below you will see that the Devon’s principal genetic problem is described in exactly these two breeds and in no others.
The curly breeds compared
The curly breeds compared · 9
| Characteristic | Devon Rex | Cornish Rex | German Rex |
|---|---|---|---|
| Gene | KRT71 (allele re) | LPAR6 | LPAR6 — the same as the Cornish |
| Inheritance | Recessive | Recessive | Recessive |
| Old label | “Gene II”, Rex Type 2 | “Gene I”, Rex Type 1 | Long thought to be separate |
| Body type | Hard, muscular, broad chest | Fine, “oriental”, arched back | Rounder, closer to the European type |
| Head | Short wedge, high cheekbones, marked “pinch” | Egg-shaped, “Roman” profile | Rounded |
| Ears | Very large, low-set, broad at the base | Large, high-set, close together | Medium, well apart |
| Hair types | All three types, but the guard hair is very sparse, short and itself rexed | No guard hair; the coat is undercoat | No guard hair |
| Texture | Soft, uneven, sparse in places | Dense, regular wave | Soft, plush |
| Cross with a Devon | — | Produces straight-coated kittens | Produces straight-coated kittens |
What a Devon Rex looks like
The Devon Rex is a small to medium cat, but nothing about it is fragile: under the coat is a hard, muscular body with a broad chest, which breed descriptions call a “hard body”. The hind legs are noticeably longer than the front ones, hence the characteristic high rear and the ability to jump onto the top of a cabinet from a standstill.
- Head: a short modified wedge, high expressive cheekbones, a short muzzle and a strong chin. The marked “pinch” — the clear narrowing behind the whisker pads — is obligatory. The skull is flat. It is the pinch and the shorter, squarer muzzle that most quickly distinguish the Devon from the Cornish, whose nose is long and narrow.
- Ears: very large, extremely broad at the base, set low and turned outward rather than upward, tapering to rounded tips. Often tufted at the tips and well furnished inside.
- Eyes: large, oval, wide apart and set at a slant, the outer corners higher than the inner ones. Any color is allowed, usually in harmony with the coat. The expression is mischievous and curious.
- Body: of medium length, muscular, with a broad chest. For all its apparent delicacy, it is not fragile.
- Legs: long and slim, the hind ones longer than the front; feet small and oval.
- Tail: long, fine, tapering, covered in short curly hair.
- Color: the standard admits every genetically possible color and pattern — solids, tabbies, bicolors, colorpoints, tortoiseshells, smokes — with any eye color. Chocolate shades close to those of the Havana Brown are as possible as anything else.
The coat: why it is uneven — and why that is normal
It is worth pausing here, because new owners are often alarmed. An ordinary cat’s coat has three layers: the long straight guard hair forms the outer covering, a finer awn hair sits below it, and the wavy down hair makes up the undercoat. In the Devon Rex, unlike the Cornish Rex, all three hair types are present — but, as the CFA breed description puts it, the guard hair is very sparse, short and itself rexed.
There are three practical consequences. First: the covering comes out “open”, the wave loose and soft, and the density is not the same all over the body — the back, flanks, belly and tail often carry noticeably sparser patches. Second: density changes — with age, with the season, with a queen’s hormonal state; a kitten may thin out temporarily and grow back in. Third, and most important for care: fine curled hair breaks easily. A stiff brush and frequent combing do not improve a Devon’s coat, they snap it off.
Another hallmark of the breed is the whiskers and eyebrows: short, crinkled, often broken off. That is not a sign of illness or of poor care, but a direct consequence of the same mutation.
Interesting facts about Devon Rexes
- The cat from the mine: Kirlee’s father was a curly-coated stray tom who kept close to a disused tin mine in Devon.
- The breed was born of a failed mating: the straight-coated kittens from the cross with Cornish Rexes proved the mutation was new — and only for that reason did the Devon become a breed of its own.
- Its closest genetic relative is the Sphynx, not the Cornish: the Sphynx’s hairlessness and the Devon’s curl are two versions of the same KRT71 gene.
- Nicknames: “elves”, “pixies”, “aliens” and “monkeys in cat suits”.
- Shoulder cats: the owner’s shoulder is a Devon’s standard observation post.
- Broken whiskers are normal for the breed: the short crinkled vibrissae snap because of the very mutation that produces the curl.
- Longhaired Devons exist: the longhair gene has been in the breed from the start — Kirlee was a proven carrier of it. British breeding policy permits breeding longhaired Devons and variants, but requires that their partners be non-carriers.
- A straight-coated Devon is still a Devon: kittens with ordinary coats from two Devon Rexes are registered as “variants” of the breed and are used fully in breeding.
- Every color at once: the standard admits any genetically possible color and pattern with any eye color.
