Splashed white 2 is part of the splash patterns and often denoted as SW2. This variety is quite different from the more famous splashed white 1, as it is located on the PAX3 gene and is a recent mutation. It has been found in a single (though large) family of quarter horses descending from the mare Katie Gun. Due to its recent origin, it can only be present in that one family of quarter horses, and not in any other breed, unless foals have been reregistered.
This pattern is not as striking as splashed white 1, though horses are known to have a lot of face white and some white on the legs.
Based upon the behaviour of the PAX3 gene in other animals, it is believed a horse homozygous for this mutation is not viable. Therefore, SW2 is seen as homozygous lethal. The embryo is likely to die in an early stage of pregnancy, and any inbreeding of horses with this gene should be avoided.