Spotted Genetics

This is one of the most frequently asked questions, "what will I get coat colour-wise, if I put my mare to Jason?"  There are many different factors that contribute to the inheritance of a spotted coat pattern.

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There is no guarantee of coat pattern when crossing two spotted horses; it can result in solid coloured as well as spotted foals; just as a spotted and a solid horse very often produce a spotted foal when bred to one another. 

If a foal appears to have been born solid, the characteristics above may start to appear (or be present) and may indicate that the horse/pony will 'colour out', and gain more spotted patterning, as it gets older.

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Hopefully these pages will go some way to explaining the basics of spotty genetics.

Leopard complex spotting (LP) is found in several breeds of horse and is characterized by the absence of pigment (white spotting) in the coat, and associated pigmentation characteristics (Bellone et al., 2013).  It's discovery in 2013 was ground-breaking in the world of spotted breeding, as it gave breeders another 'tool' with which to make educated choices, when choosing a mate for their mare.

There is no PATN2 gene that codes for blankets.  Rather, it is thought that the differing degrees of patterning 0-70%, are due to inheritance (or otherwise) of many different pattern modifiers.  These form a cumulative effect, so if more are inherited, the louder the patterning.

The Appaloosa Project is the ultimate source for people who want information on appaloosa coat colouring - it is the same genetics for all the spotted equine breeds - Appaloosa, Knabstrupper, British Spotted Pony etc.   The site/group is run be researchers, but talks plain english with great diagrams

LP determines if a horse will have a leopard complex spotting pattern while other genes determine the extent (or amount) of white patterning present. One of these genes has been identified and has been termed Pattern-1 for first pattern gene or PATN1 for short. A dominant mutation (PATN1) was identified that is associated with increased amount of white in horses that also have the LP allele.

One of the main 'enemies' to spotted breeding is the Grey Gene (G).  If this is inherited, then any pattern present at birth (and this is quite often very loud) will disappear over time.  This earns the name 'fader' as the colour will fade away.  It may happen over a period of months, or years, but eventually the G carrying horse will appear white.  This usually happens from front to back, finishing on the legs, with spots roaning before disappearing completely. Only when the horse is clipped, or washed, will the spots on the flesh beneath become apparent.