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Lp Leopard Complex Spotting

Name: Lp Leopard Complex Spotting
Brand: Equigerminal
Price: 43.05 EUR

Test that shows if your horse carries LP, the gene behind the spotted coat of the Appaloosa and the Knabstrupper....

€43.05 Inkl. mva.

About

This test shows whether your horse carries LP, the leopard complex gene behind the spotted coat of the Appaloosa and the Knabstrupper, and how many copies it has. The same gene affects the eyes: it causes night blindness and is linked to recurrent uveitis.

It is for breeders and owners of spotted horses of these and other breeds.

Why test?

Breeding. Knowing the result of both parents lets you avoid night-blind foals and plan the pattern you want.

Eye care. The result tells you which horses need the closest eye checks.

Horses with little white. Some leopard complex horses show only small signs. The test confirms whether LP is there.

Clinical signs

No copy: no leopard complex pattern.

One or two copies: a leopard complex horse. The signs most often seen:

White around the coloured part of the eye
Striped hooves
Mottled skin, pink with dark patches, around the eyes, muzzle, anus and genitals
Varnish roan: the coat loses colour with age, except over the bony parts of the face, hips and lower legs
White areas on the body, from a small blanket over the hips to a nearly white horse

One copy: usually many oval coloured spots inside the white, the classic leopard spots.

Two copies: few or no spots inside the white, as in the few-spot and snowcap patterns.

Night blindness (CSNB). The horse sees poorly in dim light and in the dark. The problem is present from birth and does not get worse.

Recurrent uveitis (ERU). Repeated inflammation inside the eye, which over time can damage sight. Watch for a sore, watery or cloudy eye.

Transmission

LP is incompletely dominant. One copy is enough for the pattern, and a second copy changes it. Night blindness needs two copies, one from each parent. The gene is not on a sex chromosome, so colts and fillies are the same.

What each mating can produce:

N/N x N/N gives 100% N/N
N/N x LP/N gives 50% N/N, 50% LP/N: no night-blind foals
N/N x LP/LP gives 100% LP/N: every foal leopard complex, none night blind
LP/N x LP/N gives 25% N/N, 50% LP/N, 25% LP/LP: one foal in four night blind
LP/N x LP/LP gives 50% LP/N, 50% LP/LP: one foal in two night blind
LP/LP x LP/LP gives 100% LP/LP: every foal night blind

Prevention

Preventing night-blind foals. Mate a leopard complex horse only with a partner that tested negative.

Looking after a night-blind horse. Take extra care when handling, turning out or travelling in poor light, and ask your veterinarian for advice.

Watching for uveitis. Ask your veterinarian to include the eyes in routine checks of every leopard complex horse. Have any eye problem seen promptly. Treatment decisions belong to your veterinarian.

Colour should not be the only thing that decides a mating. Other health traits, conformation and temperament are not read here.

Results

N/N: no copy. No night blindness and none of the uveitis risk linked to LP. Cannot pass LP on.

LP/N: one copy. Normal night vision. Higher risk of recurrent uveitis than an N/N horse. Passes LP to about half of its foals.

LP/LP: two copies. Night blind (CSNB), with the highest risk of recurrent uveitis. Passes LP to every foal.

Sample

Hair roots: 20 to 40 hairs pulled (not cut) from the mane or tail, with the roots attached. White or coloured hair both work. Tape them inside the marked area of the printable sample submission form. Hairs without roots cannot be analysed.

Blood: 5 mL of whole blood in a K3-EDTA tube, collected by a veterinarian. Label the tube with the horse's name and send it with the submission form.

Keep samples dry and at room temperature, and do not freeze them. Do not send hair that is wet, mouldy or soiled with bedding or faeces.

Turnaround

Standard processing: results within 5 to 10 working days of the sample arriving at the laboratory. Shipping is arranged and paid for by the client, and transit time is not included in the 5 to 10 working days.

Samples that fail DNA extraction or amplification are repeated at no extra cost, which may add a few working days. We contact you if a new sample is required.

How it works

🛒 Buy the test: select and buy the test online.

📧 Receive the instructions: after payment is confirmed, you receive the sample collection instructions by e-mail.

📄 Complete the form: print and complete the submission form with the animal’s identification.

✨ Collect the sample: pull 20 to 40 hair roots with the bulb and stick them in the marked area of the form, or ask your veterinarian to collect blood in a K3-EDTA tube.

📮 Send it to the laboratory: Equigerminal, S.A., HIESE, Rua da Quinta do Sobreiro, 25, Quinta Vale do Espinhal, 3230-343 Penela, PORTUGAL.

📊 Receive the report: the certified report is issued as soon as the analysis is validated.

FAQs

Will my leopard complex horse get uveitis?
Not necessarily. Most do not. LP is linked to uveitis but has not been proven to cause it. Other genes and outside factors also play a part.

What does this test not detect?
Other white patterns and the base colour. It does not diagnose uveitis.

At what age can a horse be tested?
Any age. The genotype is fixed at conception and never changes, even when the coat changes with age.

What should I order alongside it?
PATN1, the gene that decides most of how much white a leopard complex horse has, and Extension and Agouti for the colour of the spots.

For Professionals

Genetic and clinical detail for veterinarians, geneticists and laboratories.

Gene / locus: TRPM1 (transient receptor potential cation channel subfamily M member 1), Leopard complex (LP) locus, ECA1. TRPM1 is used in pigment cells and in the retina, so the variant affects both coat and night vision.
Variant: insertion of a 1,378-bp retroviral sequence in TRPM1 (Bellone et al., 2013). HGVS (EquCab3.0): NC_009144.3:g.109211964_109211965insN[1378]. Found in all 511 horses tested in the discovery study (Bellone et al., 2013).
Alternative designations: LP, Lp. Associated phenotype: congenital stationary night blindness (CSNB).
Variant identifiers: no rs/EVA identifier listed in OMIA; OMIA variant 725.
Variant classification: not currently evaluated (ISAG/AVCG, per OMIA).
Inheritance: autosomal incomplete dominant for the pattern (OMIA code AID); CSNB autosomal recessive (LP/LP only).
Penetrance / expressivity: all 10 LpLp Appaloosas had CSNB, none of 10 Lplp or 10 lplp; LpLp and Lplp horses had smaller corneal diameters than lplp (Sandmeyer et al., 2007). Amount of white is modified by PATN1 and other loci.
Breeds with documented carriers or cases: leopard complex breeds including Appaloosa, Knabstrupper, Miniature Horse, British Spotted Pony and Pony of the Americas (Holl et al., 2016; Sandmeyer et al., 2007). Association with the pattern confirmed in seven breeds (Bellone et al., 2013). A Polish study found LP in Malopolska horses, Felin ponies and Shetland ponies.
Uveitis data: ERU in 14% of 145 Appaloosas in Canada; LP/LP horses had about 19 times the odds of ERU of N/N horses and about 6 times the odds of LP/N horses (Sandmeyer et al., 2020). ERU in 20.7% of Knabstruppers (Kingsley et al., 2023).
Clinical / diagnostic notes for veterinarians: LP/LP predicts CSNB; confirmation is by full-field electroretinography: affected horses show abnormal scotopic responses with markedly reduced scotopic flicker, and altered photopic a- and b-wave parameters (Sandmeyer et al., 2007). LP is associated with equine recurrent uveitis in Appaloosas, possibly with a PATN1 contribution; the role of LP in ERU is not fully resolved (Rockwell et al., 2020). ERU diagnosis remains clinical and ophthalmological. CSNB without LP has been described in a Tennessee Walking Horse with a GRM6 missense variant (XM_001916934.4:c.533C>T; Hack et al., 2021), which this test does not detect.

Key references:

Bellone RR, Holl H, Setaluri V, et al. (2013). Evidence for a retroviral insertion in TRPM1 as the cause of congenital stationary night blindness and leopard complex spotting in the horse. PLoS One 8:e78280. doi:10.1371/journal.pone.0078280. PMID 24167615.
Sandmeyer LS, Breaux CB, Archer S, Grahn BH (2007). Clinical and electroretinographic characteristics of congenital stationary night blindness in the Appaloosa and the association with the leopard complex. Vet Ophthalmol 10:368-375. doi:10.1111/j.1463-5224.2007.00572.x.
Sandmeyer LS, et al. (2020). Vet Ophthalmol. doi:10.1111/vop.12749.
Kingsley NB, et al. (2023). Equine Vet J. doi:10.1111/evj.13879.
Rockwell H, et al. (2020). Genetic investigation of equine recurrent uveitis in Appaloosa horses. Anim Genet. doi:10.1111/age.12883.
Holl HM, Brooks SA, Archer S, et al. (2016). Variant in the RFWD3 gene associated with PATN1, a modifier of leopard complex spotting. Anim Genet 47:91-101.
Hack YL, et al. (2021). Whole-genome sequencing identifies missense mutation in GRM6 as the likely cause of congenital stationary night blindness in a Tennessee Walking Horse. Equine Vet J 53:316-323. doi:10.1111/evj.13318. PMID 32654228.