Colorpoint Restriction

Quick Summary

Cats with colored 'points' have genetic mutations associated with temperature-sensitive pigment production. Pigment production is reduced in warmer areas of the body, leading to darker pigmentation in the cat's cooler extremities (paws, ears, etc.)

Cat with 'Siamese' color points
Cat with Siamese colorpoints

Phenotype: In the Siamese phenotype, pigment expression is restricted to the cat's extremities (paws, tail, ears, face). In the Burmese phenotype, pigment expression is less temperature-sensitive, resulting in more pigment distribution across the body and points that are darker than the body.

Mode of Inheritance: Autosomal recessive (Colorpoint is recessive to Wild type); Incomplete dominance (Burmese colorpoint is incompletely dominant to Siamese colorpoint)

Alleles: C = Wild type (full color), cb = Burmese colorpoint restriction, cs = Siamese colorpoint restriction

Breeds appropriate for testing: Many breeds, particularly breeds with Asian origins

Explanation of Results:

  • Cats with C/C genotype will be full-colored and will not display colorpoint restriction. They cannot transmit colorpoint variants to any of their offspring.
  • Cats with C/cb genotype will be full-colored and are carriers of Burmese colorpoint restriction. They will transmit this Burmese colorpoint variant to 50% of their offspring. Matings between two carriers of Burmese colorpoint restriction are predicted to produce 25% Burmese colorpoint kittens.
  • Cats with C/cs genotype will be full-colored and are carriers of Siamese colorpoint restriction. They will transmit this Siamese colorpoint variant to 50% of their offspring. Matings between two carriers of Siamese colorpoint restriction are predicted to produce 25% Siamese colorpoint kittens.
  • Cats with cb/cb genotype will display Burmese colorpoint restriction and will transmit the Burmese colorpoint variant to all of their offspring.
  • Cats with cs/cs genotype will display Siamese colorpoint restriction and will transmit the Siamese colorpoint variant to all of their offspring.
  • Cats with cb/cs genotype will display Mink colorpoint restriction, an intermediate color between Siamese and Burmese.
Price

$40 one test per animal

Panels Available
Additional Details

A Burmese kitten with Burmese colorpoint restriction
Burmese kitten with Burmese colorpoint restriction

The Tyrosinase (TYR) gene, also known as the Color gene, produces an enzyme that is required for melanin production. Mutations in TYR have been associated with temperature-sensitive pigment production that result in colors known as Burmese (c.679G>T) and Siamese (c.940G>A). The wild type phenotype is full color. The Burmese phenotype results from reduced pigment production changing black pigment to sepia and orange to yellow. The Burmese points are darker than the body and the eyes are yellow-gray or yellow-green. The Siamese phenotype reduces pigment production to the points and the eyes are blue. The wild type (C) allele is dominant to Burmese (cb). Burmese is incompletely dominant to Siamese (cs); Burmese and Siamese heterozygotes (cb/cs) are intermediate in color (called 'mink').

These tests identify carriers of Burmese (also called sepia) and Siamese pointed coloration.

Turnaround Time
2-6 business days
Type of Sample

Species

Cat

Type of Test

Results Reported As
Test Result Siamese/Burmese
C/C Full color. Cat does not carry Burmese (sepia) or Siamese alleles.
C/cb Carrier of Burmese (sepia) color.
C/cs Carrier of Siamese colorpoint restriction.
cb/cb Burmese (sepia).
cs/cs Siamese.
cb/cs Mink. Intermediate color between Burmese (sepia) color and Siamese pointed phenotypes.
References

Lyons, L.A., Imes, D.L., Rah, H.C., & Grahn, R.A. (2005). Tyrosinase mutations associated with Siamese and Burmese patterns in the domestic cat (Felis catus). Animal Genetics, 36, 119-126. doi: 10.1111/j.1365-2052.2005.01253.x