Test Detail

Presence of ectopic eyelashes arising from the meibomian glands and contacting the cornea, causing chronic irritation, epiphora and keratitis or ulceration. A 16 kb intergenic deletion on ECA13 has been associated with the phenotype, without perfect concordance. Heritability uncertain. The test is complementary to the ophthalmological examination.

Frequencies and breeds: limited data.

- Ectopic eyelashes from the meibomian line
- Epiphora and blepharospasm
- Punctate keratitis and possible corneal ulcer
- Photophobia and chronic conjunctival irritation

The dossier records a 16 kb deletion on ECA13 (ECA13:g.178714_195130del), in a region involved in histone packaging, without an assigned coding gene, based on a study with 19 cases and 75 controls. No author or year is stated.

- As heritability is uncertain, do not base selection on genotype alone
- Avoid breeding clinically affected animals
- Record cases and evaluate the offspring of affected lines
- Combine ophthalmological screening with the genetic test

Differential diagnosis with trichiasis, ectopic cilia, entropion and blepharitis. Complementary: slit-lamp biomicroscopy and fluorescein staining.

1. OMIA:001841 Distiquiasis del caballo