UC Davis School of Veterinary Medicine Veterinary Genetics Laboratory
Appaloosa Pattern-1 (PATN1)

Allow 2-6 business days for coat color results

Leopard Complex spotting, a highly variable group of white spotting patterns, is controlled by the LP gene. LP determines if a horse will have a leopard complex spotting pattern while other genes determine the extent (or amount) of white. One of these genes has been identified and has been termed Pattern-1 for first pattern gene or PATN1 for short. A mutation in PATN1 was identified that is associated with increased amount of white in in LP horses. In horses that are heterozygous for LP (LP/N), presence of the PATN1 mutation most often produces a leopard or a near–leopard pattern. In horses that are homozygous for LP (LP/LP), the PATN1 mutation most often results in a few-spot or near few spot pattern. The PATN1 mutation is present in breeds with LP, including the Appaloosa, British Spotted Pony, American Miniature Horse and Knabstrupper, among others. The PATN1 mutation has been found in other breeds but may not have an effect on phenotype in the absence of LP. Testing for both LP and PATN1 is recommended for breeders interested in producing Leopard Complex-spotted horses and ponies.

The genetic basis for PATN1 has been identified. The VGL offers the test for the associated mutation. Results are reported as:


No copies of PATN1 detected.*


1 copy of PATN1 detected.*


2 copies of PATN1 detected.*

*In order for high levels of white spotting to be visible on horses that inherit PATN1, LP must also be present



Holl, H., Brooks, S.A., Archer, S., & Bellone, R.  Whole transcriptome analysis of a pattern modifier (PATN1) of Leopard Complex spotting (LP). Poster presented by H. Holl at the Plant and Animal Genome Conference XX, San Diego, CA, January 2012

Veterinary Genetics Laboratory, Tel 530-752-2211, Email VGL