DNA panel of phenotypic (aesthetic) traits specific to the Bengal that determines the genetic variants of coat colour and pattern: charcoal, chocolate, cinnamon, dilution and snow. Unlike disease panels, it does not detect pathological variants: all the traits included are exclusively cosmetic. It is performed from a buccal swab or blood and allows prediction of the expected colours and patterns in each mating. It is very useful for planning breeding programmes without resorting to test crosses.

The frequencies of the colour alleles vary enormously depending on the line and the selection objective of each programme. Snow, chocolate and dilution are relatively frequent in Bengal breeding, while charcoal is concentrated in particular lines. Population frequency data are limited and change rapidly according to selection fashions.

- Charcoal: dark dorsal cape in the form of a mantle with light periocular spectacles, a distinctive pattern of the breed\n- Chocolate and cinnamon: chocolate-brown and cinnamon-reddish coats respectively\n- Dilution: expression of blue tones (diluted black) and cream (diluted red)\n- Snow: colourpoint pattern in the Siamese or Burmese variant\n- None of the variants produces clinical signs: they are aesthetic traits

The genetics of colour in the domestic cat was built on classical inheritance studies throughout the 20th century. At the molecular level, the point variants (Siamese and Burmese) of the TYR gene were characterised in 2005, which explains the snow phenotype in the Bengal. Dilution was associated with the MLPH gene, and the chocolate and cinnamon colours with variants of the TYRP1 gene. The charcoal pattern has been associated with haplotypes of the agouti locus (ASIP) present in Bengal populations, consolidated with the creation of the breed from crosses with the leopard cat (Prionailurus bengalensis).

- Use the results to plan matings and predict litter colours without resorting to test crosses\n- Colour variants do not affect health: carriers can be mated without any restriction\n- The combination of variants (for example, dilution with chocolate or with snow) allows compound phenotypes to be obtained: plan it with the laboratory's genotype table\n- Selection for health and temperament must always take priority over colour

Remember that the charcoal pattern is not expressed as a simple recessiveness and that its prediction requires evaluating the agouti haplotypes of both parents. The snow phenotype may correspond to the Siamese or Burmese variant of TYR (or to mink compound heterozygotes), which the genetic test distinguishes. These results have no clinical implication.

1. Lyons LA et al. 2005, mutaciones de TYR asociadas con el patrón colourpoint siamés y burmés del gato. Anim Genet. PMID: 15771720
2. Lyons LA 2015, DNA mutations of the cat: the good, the bad and the ugly (revisión). PMID: 25701860
3. Gershony LC et al. 2014. Who's behind that mask and cape? The Asian leopard cat's Agouti (ASIP) allele likely affects coat colour phenotype in the Bengal cat breed. Anim Genet. PMID: 25143047