Breeds: Shetland ponies, German Riding ponies, and related breeds
Samples accepted: Blood, hair
Phenotype: Height in animals is multifactorial, meaning that it is determined by a combination of genes and environment. In ponies, one genetic variant has been found to have a comparatively large effect in Shetland ponies. A single nucleotide located in the HMGA2 gene can reduce the adult height in Shetland ponies and related breeds.
The possible genotypes are:
C/C “normal” The median, mature height of ponies with two copies of the G variant is approximately 104 cm at the withers.
A/G “middle” The median, mature height of ponies with one copy of each variant is approximately 98 cm at the withers.
A/A “short” The median, mature height of ponies with two copies of the A variant is approximately 84 cm at the withers.
This variant has not been recorded in normal sized horses.
This mutation test identifies a single nucleotide change in exon 1 of the HMGA2 gene.
Frischknecht, M., Jagannathan, V., Plattet, P., Neuditschko, M., Signer-Hasler, H., Bachmann, I., Pacholewska, A., Drögemüller, C., Dietschi, E., Flury, C., Rieder, S., Leeb, T.: A Non-Synonymous HMGA2 Variant Decreases Height in Shetland Ponies and Other Small Horses. PLoS One 10:e0140749, 2015. Pubmed reference: 26474182. DOI: 10.1371/journal.pone.0140749.
Makvandi-Nejad, S., Hoffman, G.E., Allen, J.J., Chu, E., Gu, E., Chandler, A.M., Loredo, A.I., Bellone, R.R., Mezey, J.G., Brooks, S.A., Sutter, N.B.: Four loci explain 83% of size variation in the horse. PLoS One 7:e39929, 2012. Pubmed reference: 22808074. DOI: 10.1371/journal.pone.0039929.
Signer-Hasler, H., Flury, C., Haase, B., Burger, D., Simianer, H., Leeb, T., Rieder, S.: A genome-wide association study reveals loci influencing height and other conformation traits in horses. PLoS One 7:e37282, 2012. Pubmed reference: 22615965. DOI: 10.1371/journal.pone.0037282.
Further information is available at the Online Mendelian Inheritance in Animals website.