Dilute coat colour

About the Colour

A mutation in the Dilute gene (Melanophilin, MLPH) causes dilution of coat colours. The wild-type (D) allele is dominant to the dilute (d) allele, meaning that two copies of the dilute (d) allele are required to produce the dilute colouration.

The Dilute coat colour test can be used to detect carriers of, or to confirm, the following diluted coat colour phenotypes:

Black, which is diluted Blue
Chocolate, which is diluted Lilac
Cinnamon, which is diluted to Fawn
Red, which is diluted Cream

Certain cat breeds only have the D allele (Bombay, Egyptian Mau and Singapura) or the d allele (Chartreux, Korat and Russian Blue), but most have both alleles.

Interpretation of results

Test Result Interpretation
Dilute (d/d) Has two copies of the Dilute allele (d/d) Coat colour is diluted as follows:
Black is diluted to Blue
Chocolate is diluted to Lilac
Cinnamon is diluted to Fawn
Red is diluted to Cream
Carrier of Dilute (D/d) Has one copy of the Dilute allele (D/d)
No dilution of coat colour
Does not carry Dilute (D/D) Has no copies of the Dilute allele (D/D)
No dilution of coat colour

 

FAQs

How do I test for Lilac in my Ragdolls?

Lilac is the result of the Dilute gene working on the Chocolate gene.

The results must be Chocolate (b/b) and Dilute (d/d) for the Ragdoll to be Lilac.

 

How do I test for Lilac in my British Shorthairs?

Lilac is the result of the Dilute gene working on the Chocolate or Chocolate and Cinnamon genes.

The results must be Chocolate (b/b) and Dilute (d/d) or Chocolate carrying Cinnamon (b/bI) and Dilute (d/d) for the British Shorthair to be Lilac.

 

How does Dilute work?

The Dilute gene

The Dilute gene has two alleles (D and d), with D dominant to d. When D is present (DD or Dd) the coat colour is not diluted. If a cat is dd the coat colour is diluted:

Black is diluted to Blue

Chocolate is diluted to Lilac

Cinnamon is diluted to Fawn

Red is diluted to Cream

Chocolate, Cinnamon and Dilute Colours

Chocolate/Cinnamon Dilute Coat colour
BB or Bb or BbI DD or Dd Black/Brown
BB or Bb or BbI dd Blue
bb or bbI DD or Dd Chocolate
bb or bbI dd Lilac
bIbI DD or Dd Cinnamon
bIbI dd Fawn

 

Further information

View and print 'Genetic tests for cats: what the practitioner needs to know' from our Feline Update Archive

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