DNA Tests For Cats – What Can They Tell Us?

What is a DNA test?

A DNA test is a test on the cat’s deoxyribonucleic acid (DNA) which carries genetic instructions for the sex, development, growth and function of cats. In some cases, it can also trigger disease or congenital defects. DNA is found in the cells of all living things and is located within the nucleus of every cell.

Pet owners may choose a DNA test to determine a cat’s ancestry or more importantly, obtain information about a cat’s risk of disease.

What do DNA tests detect?

Several companies now provide DNA tests for cats, each one offering a different variety of tests.

A feline DNA test can provide information on the following:

Lineage

All cat breeds descended from the African wildcat felis silvestris lybica, as they spread throughout the world, different populations emerged. For example, cats in Northern Europe developed long, thick coats which helped them to survive the harsh winters. Each of these populations of cats has slightly different markers. UC Davies has developed a test that compares a cat’s DNA with eight populations of cats around the globe.

• Western Europe: Abyssinian, American shorthair, Bengal, British shorthair, Chartreux, Cornish Rex, Egyptian Mau, Exotic shorthair, Japanese bobtail, Maine coon, Manx, Norwegian forest cat, Persian, Ragdoll, Scottish fold, Siberian, Sphynx
• South Asia: Ocicat, Birman, Burmese, Havana brown, Korat, Russian blue, Siamese, Singapura, and Australia Mist
• Eastern Mediterranean: Turkish Angora and Turkish Van
• Arabian sea: Sokoke

The sample DNA is compared to 29 cat breeds on the database and can provide information about how much DNA your cat shares with common cat breeds.

Coat colour and pattern

Mackerel tabby (uppercase A for agouti) is the wild-type coat pattern but over centuries, mutations have occurred which have lead to the varied coat colours and patterns we see now.

Agouti

• AA – Agouti (the cat will have banded hairs)
• Aa – The cat will have banded hairs, but carries the recessive non-agouti gene
• aa – The cat is non-agouti (solid or self)

Dilute

The dilute gene affects the distribution of melanin granules within the hair shaft and changes black to grey, chocolate to lilac, red to cream and cinnamon to fawn

• DD – The cat does not carry the dilute gene
• Dd – The cat is a dominant (black, chocolate, red or cinnamon) colour but carries the dilute gene
• dd – The cat is dilute

Coat length

The gene for long hair is recessive, which means the cat must carry two copies of the gene (one from each parent) for the trait to show. A shorthaired cat (we will use an uppercase S to show that it is dominant) can carry the longhaired gene (characterised by a lowercase s, which signifies it is recessive). So genetically, the shorthaired cat carrying the longhair gene would be Ss (remember, each cat carries two genes, one from the mother and one from the father.

• SS – Shorthaired cat
• Ss – Shorthaired cat carrying the longhair gene
• ss – Longhaired cat

It is important for some breeders to know if a cat carries the longhaired gene. Previously, cat breeders would have to perform test-matings to determine if a cat carried the longhair gene.

Coat type

Shorthair is the default coat type in cats, however, mutations have occurred which have changed the coat, these include longhair, hairless and the rex mutations most commonly associated with the Devon Rex and Cornish Rex.

Diseases

Over 70 genetic mutations (variants) and 250 hereditary diseases have been identified in cats that involve diseases and structural abnormalities and have been defined in the cat, many involving diseases and structural abnormalities.

A DNA test can identify inherited diseases which enables the veterinarian and owner to take early intervention and provides purebred cat breeders with the opportunity to remove high-risk cats from the breeding pool.

Diseases that can be tested for via DNA analysis include:

• Polycystic kidney disease: A progressive disease caused by multiple fluid-filled cysts in the kidneys. Small cysts are present from birth, slowly increasing in size. The increasing size of the cysts damages the normal kidney tissue, eventually causing kidney failure.
• Hypertrophic cardiomyopathy: The main feature of HCM is an excessive thickening of the left ventricular wall, papillary muscles, and septum. Enlargement of the heart wall causes stiffening of the muscle, preventing the heart from expanding to receive blood properly. As the walls thicken, the size of the heart chambers decreases resulting in less blood pumping through the heart. The heart has to work harder, beating faster to maintain blood flow throughout the body.
• Mucopolysaccharidosis: A group of lysosomal storage diseases characterised by the accumulation of mucopolysaccharides due to the impaired functions of lysosomal enzymes. Cats with MPS do not have any, or enough, of the enzymes alpha-L-iduronidase or arylsulphatase B which are needed to break down mucopolysaccharides (sugar molecule chains). Mucopolysaccharides help to build bones, cartilage, skin, tendons, corneas, and the fluid responsible for lubricating joints.
• Progressive retinal atrophy: Degeneration and atrophy of the retina, which is made of photosensitive cells known as rods and cones which convert light into electrical impulses and transport them to the brain via the optic nerve. The disease is caused by a mutation of the CEP290 gene, which encodes for the centrosomal protein 290 kDa which maintains the important structure known as the cilium in rod photoreceptors.
• Pyruvate kinase deficiency: A form of hemolytic anemia (destruction of red blood cells which occurs faster than they can be produced) caused by a deficiency of pyruvate kinase, an enzyme in red blood cells responsible. When there is a deficiency of pyruvate kinase, red blood cells cannot produce the energy they need to survive and die prematurely.
• Spinal muscular atrophy:
• Glycogen storage disease type IV: Also known as glycogenosis or dextrinosis, glycogen storage disease (GSD) is a group of rare genetic disorders characterised by an inability to metabolise glycogen, which is the stored form of sugar in the body.

Parentage

This test profiles the cat’s DNA to verify parentage, which is useful information for cat breeders to confirm a sire and dam of a cat or a litter of kittens.

Blood type

Cats have three blood groups, A, B and AB. Blood grouping is particularly important for cat breeders to prevent neonatal isoerythrolysis, a is a serious and life-threatening condition caused when kittens who have type A blood nurse from their mother who has type B blood during the first 24 hours of life. The queen’s first milk is known as colostrum contains naturally occurring alloantibodies against the kitten’s type A blood group.

Full breed profiles

Orivet offers a full breed profile that evaluates all diseases and traits such as coat colours and patterns, dilute, agouti etc., which are relevant to a particular breed.

Frequently asked questions

How is a DNA test performed?

Most DNA tests require a sample of cells from the cheek (buccal swab). This quick and easy process can be carried out at home. Blood and hair samples may be used with some DNA testing facilities.

How much do cat DNA tests cost?

The cost varies between companies as well as what information is being looked for, prices start at $100.

How long does it take to get the results?

The results of a cat DNA test can take anywhere from six to ten weeks.

 Should I have my cat DNA tested?

DNA testing can be a fun way to find out your cat’s ancestry, but more importantly, it can assess the risk of certain inherited diseases. For example, women who carry the BRCA1 or BRCA2 gene have a considerably higher risk of developing breast cancer and cats who carry certain genes have an increased risk of inherited diseases. Knowledge is power and knowing that a cat has an increased risk of certain diseases can help to prepare and make the necessary changes to slow down the progress or be on high alert.

For most pet owners, knowing a cat’s ancestry can be fun but is not necessary. However, this information for breeders can be vitally important to prevent mating cats who carry genetic mutations which can cause disease, or selecting or eliminating cats who carry certain genes which carry physical traits such as hair length, coat colour or type.