Mushroom is a unique recessive coat color type found in the Shetland Pony. In 2019 the researchers using 12 Mushroom colored horses were able to map the phenotype to a frameshift mutation in MFSD12 on equine chromosome 7. This recessive dilution gene that affects red pigment in horses. Mushroom is a unique coat color phenotype found in the Shetland Pony.
Animal Genetics offers DNA testing for the Mushroom Coat color Dilution. The genetic test verifies the presence of the MFSD12 mutation and presents results as one of the following:
|Mu/Mu||Homozygous||Horse is positive for Mushroom, and carries two inherited copies of the gene. The phenotype of the homozygous Mushroom horse will be of dilute appearance if the base coat is Red. The homozygous Mushroom specimen will pass the mutated gene to 100% of foals, but may only produce diluted offspring if bred to another Mushroom carrier.|
|n/Mu||Heterozygous||Horse has one copy of Mushroom, having inherited the trait from one parent. No visual change to carrying horse. The horse will pass the mushroom dilution gene to approximately half of foals when bred.|
|n/n||Negative||Horse can be considered a non-carrier of the Mushroom gene.|