Classic roan
White hairs mixed through a coat whose head and points remain darker
Classic roan mixes white hairs through the body while leaving the head and lower legs darker. DNA tests often use nearby markers rather than the causal variant itself. Their reliability depends on which markers are tested and whether they have been validated for the horse’s genetic background.
Explanations and diagrams reviewed on 3 November 2026
Compare four ways color and white can be arranged
This example has large white patches crossing the back and extending toward the legs.
White patches appear on the sides, with colored areas framing them along the back.
The drawing shows colored spots on a mainly white coat. The leopard complex includes other appearances too.
White hairs mix with colored body hairs. Here, the head and lower legs retain more color.
What it looks like
Classic roan mixes white and colored hairs through much of the body while the head, lower legs and much of the mane and tail stay darker. It can appear on chestnut, bay, black or a diluted base. Seasonal molting changes the contrast. A horse can therefore look very different in summer and winter without undergoing progressive graying.
Sources for this explanation [2]
What happens biologically
Research places classic roan near KIT, a gene involved in pigment-cell development. However, finding DNA markers associated with roan is not the same as proving which change causes it. A marker is a recognizable DNA difference used as a signpost; a haplotype is a group of nearby markers commonly inherited together.
In 2025, studies described haplotypes called RN1 and RN2, then an additional RN3 association in Quarter Horses. These labels distinguish marker combinations, not progressively stronger roan effects. A marker can follow the true cause closely in one family or breed and less reliably in another.
Inheritance and DNA testing
Classic roan commonly behaves as a dominant trait, meaning that one inherited roan-associated copy can produce the pattern. When a test is validated for the horse's population, one-copy and two-copy results can help estimate transmission. A one-copy parent can transmit its associated chromosome to about half its foals; a two-copy parent can transmit an associated copy to all.
For example, a one-copy parent paired with a parent without the associated markers gives an expected 50% transmission from that parent at each conception. This reasoning depends on a suitable, validated test. Ask which markers are measured and in which breeds or families they were checked: a visibly roan horse can test negative when the assay does not track its genetic cause.
Confusions, limits and health
The old claim that homozygous roan horses, with two roan-associated copies, cannot survive is unsupported: viable horses with two copies have been documented. Distinguish classic roan from progressive graying, rabicano concentrated at the flanks and tailhead, and varnish roaning associated with the leopard-complex LP variant. These mechanisms can occur together and change differently with age. Photographs from several seasons, the coat’s history and carefully interpreted DNA results tell you more than the word roan alone.
Where the explanations come from
Laboratory resources explain which variants are tested and how to read their results. Research papers describe the evidence, discoveries and remaining uncertainties. Each article links its explanations to the relevant sources. Published titles stay in their original language so you can find the exact work.
1 · Laboratory explanation
UC Davis VGL — Leopard complex, congenital stationary night blindness and uveitis2 · Laboratory explanation
UC Davis VGL — Roan zygosity test3 · Research paper
Voß et al. (2020) — Coat color roan shows association with KIT variants and no evidence of lethality in Icelandic horses4 · Research paper
Everts et al. (2025) — Identification of two genetic haplotypes associated with the roan coat color in the American Quarter Horse and other equine breeds5 · Research paper
Everts et al. (2025) — Identification of a novel haplotype associated with roan coat color in American Quarter Horses