OMIA:002197-9796 : Coat colour, phaeomelanin dilution, MFSD12-related in Equus caballus (horse)

In other species: dog

Categories: Pigmentation phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 617745 (gene)

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive

Considered a defect: no

Key variant known: yes

Year key variant first reported: 2019

Cross-species summary: pheomelanin dilution, pigment intensity

Species-specific description: Tanaka et al. (2019): "Mushroom is a unique coat color phenotype in Shetland Ponies characterized by the dilution of the chestnut coat color to a sepia tone".

Mapping: Tanaka et al. (2019) mapped this locus to chromosome ECA7.

Molecular basis: Tanaka et al. (2019) provided evidence supporting a frameshift mutation (p.Asp201fs) in the MFSD12 gene as being a likely causal variant for the mushroom coat colour: "This variant was perfectly concordant with phenotype in 96 Shetland Ponies (P = 1.15 × 10-22), was identified in the closely related Miniature Horse for which the mushroom phenotype is suspected to occur (fmu = 0.02), and was absent in 252 individuals from seven additional breeds not reported to have the mushroom phenotype. MFSD12 is highly expressed in melanocytes and variants in this gene in humans, mice, and dogs impact pigmentation." Currently no 'gene link' to NCBI; and ENSEMBL is incorrectly associating MFSD12 with 'CACTIN'.

Breed: Shetland Pony (Horse) (VBO_0001066).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
MFSD12 major facilitator superfamily domain containing 12 Equus caballus 7 NC_009150.3 (2549382..2541111) MFSD12 Homologene, Ensembl , NCBI gene


By default, variants are sorted chronologically by year of publication, to provide a historical perspective. Readers can re-sort on any column by clicking on the column header. Click it again to sort in a descending order. To create a multiple-field sort, hold down Shift while clicking on the second, third etc relevant column headers.

WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.

Since October 2021, OMIA includes a semiautomated lift-over pipeline to facilitate updates of genomic positions to a recent reference genome position. These changes to genomic positions are not always reflected in the ‘acknowledgements’ or ‘verbal description’ fields in this table.

OMIA Variant ID Breed(s) Variant Phenotype Gene Allele Type of Variant Source of Genetic Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
1426 Shetland Pony (Horse) Coat colour, dilution (mushroom) MFSD12 Mu duplication Naturally occurring variant EquCab3.0 7 NC_009150.3:g.2544518dup XM_023646425.1:c.600dup XP_023502193.1:p.(D201fs) XM_023646425.1; XP_023502193.1; published as NC_009150.3: g.2544512dup (XM_023646425.1:c.600dupC, p.Asp201fs); coordinates in the table have been updated to reflect HGVS nomenclature 2019 31635058

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2024). OMIA:002197-9796: Online Mendelian Inheritance in Animals (OMIA) [dataset].


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.

2019 Tanaka, J., Leeb, T., Rushton, J., Famula, T.R., Mack, M., Jagannathan, V., Flury, C., Bachmann, I., Eberth, J., McDonnell, S.M., Penedo, M.C.T., Bellone, R.R. :
Frameshift variant in MFSD12 explains the mushroom coat color dilution in Shetland Ponies. Genes (Basel) 10:826, 2019. Pubmed reference: 31635058. DOI: 10.3390/genes10100826.
Tanaka, J.L., Leeb, T., Mack, M., Jagannathan, V., Flury, C., Bachmann, I., McDonnell, S., Penedo, M.C., Bellone, R.R. :
A frameshift variant in MFSD12 explains the mushroom coat Color dilution in Shetland Ponies. PAG XXVII :W355, 2019.

Edit History

  • Created by Frank Nicholas on 23 May 2019
  • Changed by Frank Nicholas on 23 May 2019
  • Changed by Frank Nicholas on 03 Feb 2020
  • Changed by Imke Tammen2 on 10 Feb 2022
  • Changed by Imke Tammen2 on 03 Jun 2024