Astenia Dérmica Regional Equina Hereditaria - HERDA
Prueba de ADN para Astenia Dérmica Regional Equina Hereditaria (HERDA). Esta prueba verifica la presencia del gen HERDA recesivo. Muestra 30...
€43.05 IVA incluido
Acerca de la prueba
La Prueba de ADN HERDA detecta la presencia de la mutación recesiva responsable de la Dermatosis Regional Equina Hereditaria (HERDA).
Esta prueba genética identifica caballos que son libres, portadores o afectados por HERDA, ayudando a los criadores a tomar decisiones informadas de cría y prevenir la producción de potros afectados.
¿Por qué probar?
La prueba de HERDA ayuda a:
- Identificar caballos portadores de la mutación HERDA.
- Evitar el apareamiento de dos caballos portadores.
- Prevenir el nacimiento de potros afectados.
- Apoyar programas de cría responsables.
- Confirmar el estado genético de los animales reproductores.
Signos clínicos
Affected foals rarely show anything at birth. Serious skin damage starts on average at about a year and a half and is usually noticed between 18 and 24 months, often when the horse is first broken to saddle. A knock or a rub can bring it out as early as 6 months, and a few horses show nothing until they are four or five.
- Swellings under the skin, filled with fluid or blood, which owners often call blisters. This is the most common first sign.
- Loose skin that lifts away easily when pinched and does not spring back
- Open wounds, skin that comes away from ordinary contact, and wounds that heal badly
- Disfiguring scars, with thin white hairs where the coat grows back
- Damage along the back from the withers to the croup, and also over the hindquarters, neck, sides of the chest and belly, lower legs, face, top of the tail and coronary band
- The skin damage does not itch and is not painful in itself, but large open areas and blood-filled swellings do hurt and change the horse's behaviour
- Heat and sunlight make it worse; several weeks kept in a stable tend to improve it
- Ulcers on the surface of the eye, weaker tendons and ligaments in the lower leg and a higher risk of arthritis have also been described
- Two affected horses have been reported with a skin cancer that spread through the body
None of these signs is unique to HERDA. Your veterinarian makes the diagnosis, using the history, the examination and this result.
Transmisión
HERDA is recessive. A foal needs one copy from the sire and one from the dam to be affected. The gene is not on a sex chromosome, so colts and fillies are affected equally.
What each mating can produce:
- n/n x n/n gives 100% n/n
- n/n x n/HERDA gives 50% n/n, 50% n/HERDA
- n/n x HERDA/HERDA gives 100% n/HERDA
- n/HERDA x n/HERDA gives 25% n/n, 50% n/HERDA, 25% HERDA/HERDA
- n/HERDA x HERDA/HERDA gives 50% n/HERDA, 50% HERDA/HERDA
- HERDA/HERDA x HERDA/HERDA gives 100% HERDA/HERDA
Prevención
There is no cure, so prevention is a breeding decision.
Breeding. Mate a carrier only with a partner that tested negative, and test every foal. No affected foals are born, though some foals will be carriers. This keeps a valuable line while the variant is bred out. Being a carrier is not by itself a reason to stop breeding a horse.
Managing an affected horse. An affected horse can be kept comfortable, but no treatment restores the skin. Many are put down because they cannot be ridden and should not be bred from. Your veterinarian guides riding, wound care and quality of life.
Resultados
La prueba de ADN verifica la presencia del gen recesivo HERDA y presenta los resultados como uno de los siguientes:
- N/ - Negativo para HERDA. Ausencia del gen defectuoso responsable de HERDA.
- N/HERDA - Portador - Heterocigoto positivo para HERDA. Presencia de una copia del alelo responsable de HERDA. El caballo es portador de HERDA y puede transmitir una copia del alelo HERDA a su descendencia cuando se reproduce.
- HERDA/ - Homocigoto positivo para HERDA. Presencia de dos copias del alelo responsable de HERDA. El caballo está afectado por el trastorno HERDA y puede transmitir el alelo HERDA al 100% de su descendencia cuando se reproduce.
Requisitos de muestra
30 a 40 - raíces del cabello - sobre o 5 mL - sangre - tubo K3 EDTA
Envía tu muestra por correo ordinario o entrega exprés a:
Laboratorio Equigerminal HIESE
Rua da Quinta do Sobreiro Nº25
3230-343 Penela, Portugal
Tiempo de entrega
2 a 5 días hábiles
Cómo funciona
🛒 Compra el Test: Selecciona y compra el test en línea.
📧 Recibe Instrucciones: Después de la confirmación del pago, recibe instrucciones para la recolección de la muestra.
✨ Recolección de Muestra: Tu veterinario recoge la muestra o recoge las raíces del pelo según las instrucciones proporcionadas.
📄 Descarga el Formulario de Envío: Descarga el formulario de envío imprimible.
📮 Envía las Muestras: Envía a:
Equigerminal Lab HIESE
Rua da Quinta do Sobreiro Nº25
3230-343 Penela, Portugal
📄 Recibe Resultados: Tu certificado de prueba de ADN será enviado por correo electrónico.
Preguntas frecuentes
¿Qué es HERDA?
HERDA es un trastorno hereditario de la piel que causa una piel extremadamente frágil, mala cicatrización de heridas y cicatrices severas en los caballos afectados.
¿Pueden los caballos portadores desarrollar la enfermedad?
No. Los caballos portadores están clínicamente sanos pero pueden transmitir la mutación HERDA aproximadamente al 50% de su descendencia.
¿Qué razas son las más comúnmente afectadas?
HERDA ocurre predominantemente en caballos American Quarter, especialmente en líneas de caballos de cutting, aunque razas relacionadas también pueden portar la mutación.
¿Se puede prevenir HERDA?
Sí. Realizar pruebas de ADN a los animales reproductores y evitar apareamientos entre portadores previene el nacimiento de potros afectados.
¿Cuándo se debe hacer la prueba a un caballo?
Cualquier caballo destinado a la reproducción, especialmente los Quarter Horses y razas relacionadas, debe ser probado antes del apareamiento para determinar su estado genético.
For Professionals
Genetic and clinical detail for veterinarians, geneticists and laboratories.
- Gene / locus: PPIB (peptidylprolyl isomerase B, cyclophilin B), ECA1.
- Variant: G39R (Gly39Arg), missense. HGVS (EquCab3.0): NC_009144.3:g.129307092G>A; NM_001099761.1:c.115G>A; NP_001093231.1:p.(Gly39Arg).
- Alternative designations: G6R in Ishikawa et al. (2012), counted from a different starting residue of the protein; both names denote the same change. Disease synonyms: hereditary (heritable) equine regional dermal asthenia, hyperelastosis cutis.
- Variant identifiers: rs396329681 (EVA); OMIA variant 157.
- Variant classification: not currently evaluated (ISAG/AVCG, per OMIA).
- Mechanism: isomerase activity preserved, but cyclophilin B protein interactions and collagen folding are altered, so dermal collagen is abnormal (Ishikawa et al., 2012).
- Inheritance: autosomal recessive (OMIA code R; Tryon et al., 2005). Generally attributed to a founder effect.
- Breeds with documented carriers or cases: Quarter Horse (OMIA variant record); affected American Paint Horses and Appaloosas also reported, both registries with Quarter Horse ancestry. Of 58 affected horses, 52 Quarter Horses, 4 Paints, 2 Appaloosas (Tryon et al., 2005); of 50 affected horses, 43 Quarter Horses, 1 Quarter Horse cross, 4 Paints, 2 Appaloosas (White et al., 2004).
- Allele / carrier frequencies: carrier frequency 3.5% (38 of 1,079 unaffected control Quarter Horses; Tryon et al., 2007). Carrier frequency by discipline about 28% in cutting, 12.8% in western pleasure and 11.5% in working cow horses, and 1.7% in American Paint Horses (Rashmir-Raven, 2013). Carrier frequency 1.6% (2 of 125 Quarter Horses in France, both mares; White and Bourdeau, 2011). Allele frequency 13.5% in elite cutting Quarter Horses, with no change over time in the random cohort (Brown et al., 2026; 300 performance and 300 random horses born 2020 to 2024). Carrier and allele frequencies are not interchangeable; for a rare recessive the allele figure is roughly half the carrier figure.
- Clinical / diagnostic notes for veterinarians: age at first owner observation ranged from birth to four years in the White et al. (2004) series. None of those 50 horses had joint hyperlaxity or visceral involvement; later work describes joint laxity at birth in some foals, and viscera were normal in the foal and dam followed by White et al. (2007). Corneal thinning has been described. One adult HERDA/HERDA horse was reported working normally with mild signs (Patterson Rosa et al., 2021), so genotype does not predict severity. Skin biopsy is a separate procedure; histopathology is suggestive but not diagnostic, and suspected cases should be confirmed by genotyping. Fragile-skin disease not caused by this variant occurs, including in a Quarter Horse gelding (Steelman et al., 2013).
Key references:
- Tryon RC, White SD, Bannasch DL (2007). Homozygosity mapping approach identifies a missense mutation in equine cyclophilin B (PPIB) associated with HERDA in the American Quarter Horse. Genomics 90:93-102. doi:10.1016/j.ygeno.2007.03.009. PMID 17498917.
- Tryon RC, White SD, Famula TR, Schultheiss PC, Hamar DW, Bannasch DL (2005). Inheritance of hereditary equine regional dermal asthenia in Quarter Horses. Am J Vet Res 66:437-442. doi:10.2460/ajvr.2005.66.437.
- White SD, Affolter VK, Bannasch DL, Schultheiss PC, Hamar DW, Chapman PL, et al. (2004). Hereditary equine regional dermal asthenia (hyperelastosis cutis) in 50 horses: clinical, histological, immunohistological and ultrastructural findings. Vet Dermatol 15:207-217. doi:10.1111/j.1365-3164.2004.00402.x.
- Ishikawa Y, Vranka JA, Boudko SP, et al. (2012). Mutation in cyclophilin B that causes hyperelastosis cutis in American Quarter Horse does not affect peptidylprolyl cis-trans isomerase activity but shows altered cyclophilin B-protein interactions and affects collagen folding. J Biol Chem 287:22253-22265. doi:10.1074/jbc.M111.333336.
- White SD, Bourdeau P (2011). Prevalence of the mutation in cyclophilin B (PPIB), a causal candidate gene for HERDA, among Quarter Horses in France. Vet Dermatol 22:206-208. doi:10.1111/j.1365-3164.2010.00941.x.
- Rashmir-Raven A (2013). Heritable equine regional dermal asthenia. Vet Clin North Am Equine Pract 29:689-702. doi:10.1016/j.cveq.2013.09.001.
- Brown BN, Hughes S, Le TM, Tatar NP, Grahn JC, Carrillo-Alvarez M, Bellone RR, Finno CJ (2026). Allele frequencies of 7 inherited disorders in performance and random cohorts of American Quarter Horses (2020-2024). J Am Vet Med Assoc 1-7. doi:10.2460/javma.26.04.0256.