• About This Guide
  
• How This Guide is Being Developed
  
• Philosophy of this guide
  
• Using this Guide
  
• Thinking Scientifically
  
• About the Author
  
• Documented Genes
  
• What is a documented gene?
  
• Black/Red (MC1R)
  
• Bay (ASIP)
  
• Cream/Pearl (SLC45A2)
  
• Dun (TBX3)
  
• Gray (STX17)
  
• Silver (PMEL17)
  
• Champagne (SLC36A1)
  
• Roan/Tobiano/Sabino/White Spotting (KIT)
  
• Splash White (MITF/PAX3)
  
• Leopard Complex (TRPM1/ECA3P)
  
• Frame (EDNRB)
  
• Tiger Eye (SLC24A5)
  
• Height Regulation (HMGA2/LCORL)
  
• Mushroom (MFSD12)
  
• Hypothetical Genes
  
• What is a hypothetical gene?
  
• Borrowed Genes
  
• Glossaries
  
• Glossary of Colors
  
• Glossary of Terms
  

Cream/Pearl (SLC45A2)

• Last updated: 2026-01-30

  Common Names: Cream, Pearl, Sunshine, Snowdrop

  Scientific Name: solute carrier family 45 member 2 (SLC45A2) or Membrane-associated transporter protein (MATP)

  Equine Chromosome: 21

  General Overview:

  The cream mutation of SLC45A2, often noted as Cr, is an incompletely dominant dilution gene that reduces pigmentation in the eyes and coat. [1] One copy of cream has a moderate dilution effect that turns red pigment into shades of gold and buff. It has minimal to no visible effect on black pigment [2]. One copy of cream, turns black horses smoky black, bays into buckskins and chestnuts into palominos.
  
  When two copies of the cream mutation are present there is significant reduction in both black and red pigment resulting in cream colored horses with blue eyes and pink skin.[1] Two copies turn black horses into smoky creams, bays into perlinos, and chestnuts into cremellos. 

  
  

  Pearl is another mutation located on SLC45A2, often marked as Prl. Pearl dilutes both red and black pigment equally, but to a much lesser degree than cream. [3] One copy results in a horse with normal coloration but may have very slight dilution or skin mottling. [4] Two copies of pearl produce a uniform apricot color with paler than normal skin. Eyes tend to be amber to green in hue. [3]

  
  

  Sunshine (C^sun) is a pearl-like dilution of SLC45A2. It has no known impact when heterozygous and produces a pearl-like appearance when homozygous. This mutation was originally found only in Standardbred X TWH cross named Captain Sunshine.[5], but it was announced that the gene was also found in an unrelated Tennessee Walking Horse in January 2026.[7]

  
  

  Snowdrop (C^sno) is a recessive dilution of SLC45A2. It has no visible effect when heterozygous, and produces a pseudo double cream appearance when homozygous. This mutation is only known from one line of Vanner horses. [6]

  
  

  All known mutations of SLC45A2 amplify one another. When combined they often produce cream colored coats, with pink skin and blue eyes.

• Citations:

  1. Mariat D, Taourit S, Guérin G. A mutation in the MATP gene causes the cream coat colour in the horse. Genet Sel Evol. 2003 Jan-Feb;35(1):119-33. doi: 10.1186/1297-9686-35-1-119. PMID: 12605854; PMCID: PMC2732686. https://hal.science/hal-00894438v1/file/hal-00894438.pdf
  2. “Cream | Veterinary Genetics Laboratory.” Vgl.ucdavis.edu, vgl.ucdavis.edu/test/cream
  3. Sevane N, Sanz CR, Dunner S. Explicit evidence for a missense mutation in exon 4 of SLC45A2 gene causing the pearl coat dilution in horses. Anim Genet. 2019 Jun;50(3):275-278. doi: 10.1111/age.12784. Epub 2019 Apr 10. PMID: 30968968. https://www.ucm.es/data/cont/docs/345-2019-04-11-... 
  4. Sponenberg D.P. & Bellone R. (2017) Equine Color Genetics, 4th edn. John Wiley & Sons, Hoboken, NJ.
  5. Holl HM, Pflug KM, Yates KM, Hoefs-Martin K, Shepard C, Cook DG, Lafayette C, Brooks SA. A candidate gene approach identifies variants in SLC45A2 that explain dilute phenotypes, pearl and sunshine, in compound heterozygote horses. Anim Genet. 2019 Jun;50(3):271-274. doi: 10.1111/age.12790. Epub 2019 Apr 21. PMID: 31006892.
     https://onlinelibrary.wiley.com/doi/10.1111/age.12790
  6. Bisbee D, Carpenter ML, Hoefs-Martin K, Brooks SA, Lafayette C. Identification of a novel missense variant in SLC45A2 associated with dilute snowdrop phenotype in Gypsy horses. Anim Genet. 2020 Mar;51(2):342-343. doi: 10.1111/age.12913. Epub 2020 Jan 21. PMID: 31961951. https://www.researchgate.net/publication/337464050... 
  7. Etalon Equine Genetics (2026, January 30) NEW SUNSHINE DISCOVERY UPDATE! [Status update]. Facebook. https://www.facebook.com/share/p/1DUBLaNH16/

• Examples:

  Bay E/? a/a -/-, Smoky Black E/? a/a Cr/-, Smoky Cream E/? a/a Cr/Cr

  

  
  

  Bay E/? A/? -/-, Buckskin E/? A/? Cr/-, Perlino E/? A/? Cr/Cr

  

  
  

  Chestnut e/e -/-, Palomino e/e Cr/-, Cremello e/e Cr/Cr

  

  
  

  Black Pearl Carrier E/? a/a Prl/-, Black Pearl E/? a/a Prl/Prl, Smoky Black Pearl E/? a/a Prl/Cr

  

  
  

  Bay Pearl Carrier E/? A/? Prl/-, Bay Pearl E/? A/? Prl/Prl, Buckskin Pearl E/? A/? Prl/Cr

  

  
  

  Chestnut Pearl Carrier E/? Prl/-, Chestnut Pearl E/? A/? Prl/Prl, Palomino Pearl E/? A/? Prl/Cr