OMIA 002175-9796 : Curly coat with hypotrichosis in Equus caballus

Mendelian trait/disorder: no

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2018

Inheritance: Thomer et al. (2018) reported that genotypes at two genes, KRT25 and SP6, each with two alleles, could explain all combinations of curly +/- and hypotrichosis +/-: "Horses heterozygous or homozygous only for KRT25 variant [see below] showed curly coat and hypotrichosis, whereas horses with SP6 variant [see below] only, exhibited curly coat without hypotrichosis. Horses with mutant alleles in both variants developed curly hair and hypotrichosis. Thus, mutant KRT25 allele is masking SP6 allele effect, indicative for epistasis of KRT25 variant over SP6 variant."

Molecular basis: Thomer et al. (2018) identified two likely causal variants: g.21891160G>A; p.R89H in the KRT25 gene, and g. 24022045C>T; p.G364S in the SP6 gene. An independent discovery of the KRT25 variant in relation to Curly coat (see OMIA 000245-9796) was published while the MS by Thomer et al. was undergoing peer review. As explained in the Inheritance section, Tomer et al. (2018) "demonstrated an epistatic effect of KRT25 variant on SP6 variant due to its pleiotropy on hair structure and hair loss."

Breeds: American Bashkir Curly horse, Missouri Foxtrotter.

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
SP6 Sp6 transcription factor Equus caballus 11 NC_009154.3 (24099790..24093883) SP6 Homologene, Ensembl, NCBI gene

Variants

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.

Breed(s) Variant Phenotype Gene Allele Type of Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
American Bashkir Curly horse Missouri Foxtrotter Curly coat with/without hypotrichosis SP6 missense EquCab3.0 11 g.24096309C>T c.1090G>A p.Asp364Asn Thomer et al. (2018): "SP6; NC_009154.2:g.24022045C>T, ss3021042887" with respect to EquCab2. Updated coordinates in this entry obtained from EVA rs1095048852; 14 Mar 2019 rs1095048852 2018 29686323

Reference


2018 Thomer, A., Gottschalk, M., Christmann, A., Naccache, F., Jung, K., Hewicker-Trautwein, M., Distl, O., Metzger, J. :
An epistatic effect of KRT25 on SP6 is involved in curly coat in horses. Sci Rep 8:6374, 2018. Pubmed reference: 29686323. DOI: 10.1038/s41598-018-24865-3.

Edit History


  • Created by Frank Nicholas on 14 Mar 2019
  • Changed by Frank Nicholas on 14 Mar 2019