OMIA 001841-9796 : Distichiasis in Equus caballus

In other species: dog , cattle

Possibly relevant human trait(s) and/or gene(s) (MIM number): 126300

Mendelian trait/disorder: unknown

Considered a defect: yes

Cross-species summary: Two rows of eyelashes

Molecular basis: Hisey et al. (2020) conducted a genome wide association study, mapped distichiasis to ECA13 and "identified a 16 kb deletion on ECA13 in an intergenic region that was associated with distichiasis in Friesian horses. .... The identified 16 kb deletion (ECA13:g.178714_195130del) was also not perfectly concordant with disease but was the most concordant with disease phenotype. ... Eighteen out of 19 cases were homozygous for the 16 kb deletion; however, seven out of 75 controls were also homozygous for the deletion. ... A single horse with distichia was not homozygous for the ROH identified as a part of the GWAS analysis and was heterozygous for the deletion."

Clinical features: Hisey et al. (2020): "These misplaced cilia can cause discomfort, chronic keratitis, and corneal ulceration, potentially impacting vision due to corneal fibrosis, or, if secondary infection occurs, may lead to loss of the eye."

Breed: Friesian.

References


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.
2020 Hisey, E.A., Hermans, H., Lounsberry, Z.T., Avila, F., Grahn, R.A., Knickelbein, K.E., Duward-Akhurst, S.A., McCue, M.E., Kalbfleisch, T.S., Lassaline, M.E., Back, W., Bellone, R.R. :
Whole genome sequencing identified a 16 kilobase deletion on ECA13 associated with distichiasis in Friesian horses. BMC Genomics 21:848, 2020. Pubmed reference: 33256610. DOI: 10.1186/s12864-020-07265-8.
2014 Hermans, H., Ensink, J.M. :
Treatment and long-term follow-up of distichiasis, with special reference to the Friesian horse: a case series. Equine Vet J 46:458-62, 2014. Pubmed reference: 23927412. DOI: 10.1111/evj.12157.

Edit History


  • Created by Imke Tammen2 on 08 Dec 2020
  • Changed by Imke Tammen2 on 08 Dec 2020