Dominant White 8 (W8)
Dominant White 8, also known as W8, is a dominant white spotting pattern that can appear on all three base coat colors.
W8 horses typically have irregular white markings with jagged edges, often including extensive facial markings, white legs, and scattered white hairs throughout their coat. The pattern can sometimes be confused with Sabino (SB1) due to it's very similar appearance.
How W8 Works In-Game
In game, W8 horses can display white spotting across their body, with irregular patches and white ticking that can give the coat a roaned appearance, this gene is not to be confused with the actual Roan (RN) gene however.
The amount and distribution of white can vary, with some horses displaying more extensive white markings than others.
W8 does not change the horse's underlying base coat colour, although other white spotting patterns and modifiers may influence the resulting appearance, especially if multiple white markings are stacked.
W8 Inheritance
Because W8 is dominant, only one copy is needed for the pattern to visually show on a horse.
- W8/W8 - The horse has two copies of W8. This combination is a homozygous lethal.
- W8/n - The horse has one copy of W8 and will have a 50% chance of passing W8 to its offspring.
- n/n - The horse does not have the W8 gene and will not visually display it or be able to pass it to its offspring.
Embryonic Lethals
W8 is believed to be potentially embryonic lethal when a horse inherits two copies of the gene. This means that an affected embryo may fail to develop, resulting in loss of the pregnancy before the foal is born.
Because W8 and other Dominant White variants, such as W21, affect the same KIT gene, inheriting two different variants may also carry a risk of embryonic lethality. However, combinations such as W8/W21 have not been confirmed to be lethal, and not all Dominant White combinations have the same effects.
In game, horses carrying W8/W8, W21/21 or a combination (W8/W21) will result in a lethal combination. This would typically result in the foal passing away before it is born, however in game the foal will display similar to one impacted by LWO (Lethal White Overo Syndrome) - it will be born however will pass away before growing into an adult.
When breeding a horse carrying W8 (W8/n) with a horse carrying W21 (W21/n), the resulting probabilities are:
- 25%- W8/W21 - One copy of each variant. Homozygous lethal.
- 25% - W8/n - One copy of W8, allowing the horse to display the pattern.
- 25% - W21/n - One copy of W21, allowing the horse to display the pattern.
- 25% - n/n - No copies of either variant.
Breeding two horses carrying the same variant (W8/n × W8/n or W21/n × W21/n) also produces a 25% chance of inheriting two copies of that variant.
Because of this, breeding two W8/21 carriers together comes with a risk of producing a foal inherting two copies of either gene - you may still breed them together, however you understand the risks associated with doing so.
Genetic Testing
W8 is a genetically identified white spotting pattern associated with the KIT gene in real horses. The gene was originally identified in Icelandic Horses.
In our genetics system, W8 is a testable white marking. Players can have their horses genetically tested at a veterinary office to determine whether they carry the W8 gene.