Roan is a dominant gene, producing white hairs throughout the coat. It can be affected by the W20 gene, producing a horse with more white hairs. The gene is found on the KIT locus with tobiano, sabino and W20. Roan does not appear on foals.
| Genetic Panel |
| KIT |
| Rn/Rn Rn/n or n/Rn Sb/Rn or Rn/Sb To/Rn or Rn/To Rn/W20 or W20/Rn |
| Patterns | |
| Minimal Roan | Classic Roan |
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| Extensive Roan | |
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