What is a dilute tortie cat?

Also known as a muted tortie, a dilute tortie is a type of coat colour and pattern which consists of grey and cream markings.

This striking coat pattern is the dilute form of the more traditional black and red (orange) tortie pattern. Tortoiseshell almost exclusively occurs in female cats as the orange gene is located on the X chromosome, as the male (XY) only inherits one copy of the X chromosome he will either be orange or non-orange. As a female cat (XX) has two X chromosomes, if she inherits one copy of the orange gene, and one copy of black, she will be tortoiseshell. The dilute gene changes black and red to grey and cream.

Mode of inheritance

Dilution is recessive, therefore the cat must inherit two copies of the dilute gene (one from each parent) for dilution to occur.

Genetic codes: Dominant genes are always characterised by an UPPERCASE letter, recessive ones are always lowercase. D (dense), d (dilute).

• Homozygous dense (D/D): Black and red tortie or less commonly brown and red
• Heterozygous dense carrying dilute (D/d): Black and red tortie or less commonly brown and red tortie
• Homozygous dilute (d/d): Grey and cream or less commonly lilac and cream

How the dilute gene affects coat colours

Dilution is the result of a single base deletion in the melanophilin (MLPH) gene which provides instructions for making melanophilin, a carrier protein that is found in pigment-producing melanocytes.

The muted coat colours are due to the dilute gene, which is caused by a single base deletion in the melanophilin (MLPH) gene. This gene provides instructions for making melanophilin, a carrier protein that is found in pigment-producing melanocytes. Melanophilin is essential for the even distribution, transport, and translocation of melanin (pigment granules). Menalocytes are specialised cells that contain organelles known as melanosomes. Melanosomes synthesise, store and transport melanin out of the cell via the dendrites to neighbouring keratinocytes (keratin-producing cells).

Melanin synthesis is normal, however, pigment granules are enlarged and deposited unevenly in the hair. This result is clumps of melanin in varying sizes along the hair shaft and areas which lack pigment, producing the illusion of a lighter coat colour.

Effects of the dilute gene

Dense	Dilute
Black	Grey (blue)
Red	Cream
Chocolate	Lilac
Cinnamon	Fawn

Frequently asked questions

What breed is a dilute tortie?

A dilute tortie is a coat colour/pattern and not a breed and is found in both random-bred as well as purebred cat populations.

Are dilute torties rare?

While grey and cream torties are relatively common, lilac and cream, fawn and cream are uncommon.

How much is a dilute tortie worth?

The best place to adopt a mixed breed dilute tortie is from a rescue organisation or animal shelter, with an average cost ranging from $100 to $300. This will include the first vaccination, worming, desexing and microchipping. A purebred dilute tortie can vary from $1,000 to $5,000 depending on the breed.

Which breeds accept dilute tortie?

Dilute tortie can be found in the following breeds:

• American Wirehair
• British Shorthair
• Cornish Rex
• Devon Rex
• Exotic shorthair
• LaPerm
• Maine Coon
• Munchkin
• Norwegian Forest Cat
• Persian
• Scottish Fold
• Scottish Shorthair
• Sphynx

Are there any male dilute torties?

Dilute male torties are rare with an incidence of 1 in 3,000 and are usually associated with Klinefelter syndrome which is a condition where the male inherits an extra X chromosome, ie; XXY instead of XY. Male torties are almost always sterile.

How long do dilute torties live?

The lifespan of a dilute tortie is the same as any other colour, with an average lifespan between 12-15 years.

What is the difference between a dilute tortie and a dilute calico?

A dilute tortie consists of patches of grey, lilac or fawn and cream while the calico cat also has patches of white.

Feature image: Alena Mozhjer, Shutterstock