Produktformular

Glykogenforgrenende enzymmangel - GBED

Name: Glykogenforgrenende enzymmangel - GBED
Brand: Equigerminal
Price: 43.05 EUR

DNA-test for Glycogen Branching Enzyme Deficiency (GBED). Denne DNA-test verificerer tilstedeværelsen af den recessive GBED-allel. Eksempel 30 til 40 - hårrødder...

€43.05 Inkl. moms

Om testen

DNA-testen forglykogenforgreningsenzymdefekt (GBED)påviser den recessive mutation, der er ansvarlig for glykogenforgreningsenzymdefekt, en dødelig arvelig lidelse, der påvirker glykogenmetabolismen.

GBED nedarves som enautosomal recessivegenskab. Bærerheste er klinisk normale, men kan give mutationen videre til deres afkom. Føl, der arver to kopier af mutationen, er ude af stand til at lagre glykogen korrekt, hvilket resulterer i abort, dødfødsel eller død kort efter fødslen.

DNA-testning gør det muligt for opdrættere at identificere bærere og træffe informerede avlsbeslutninger for at forhindre ramte føl.

Hvorfor teste?

Test for GBED giver opdrættere mulighed for at:

Identificere klinisk normale bærere.
Forhindre parring mellem to bærere.
Reducere risikoen for aborter og føl med sygdommen.
Bekræfte mistænkte tilfælde af GBED hos føl.
Støtte ansvarlige avlsprogrammer.

GBED forekommer hyppigst hos Quarter Horses, Paint Horsesog beslægtede racer.

Kliniske tegn

Many affected foals are aborted or born dead. Of those born alive, most died or were put down by 8 weeks old in the published cases, and none has been found to live past 18 weeks.

Abortion late in the pregnancy, a foal born dead, or a foal born early
Weakness all over, unable to stand or to suck, lying down and not getting up
Legs that come up bent and contracted, which then straighten out again
Fits, in some foals because the blood sugar has fallen too low
Fast breathing and a fast heart, breathing failure, an irregular heartbeat, and sudden death, including after exercise
On blood tests: a low white cell count, raised muscle enzymes, and blood sugar that keeps dropping
After death the organs look almost normal to the eye

None of these signs is unique to GBED, and it is easily mistaken for other newborn diseases. Your veterinarian or a pathologist makes the diagnosis.

Transmission

GBED 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/GBED gives 50% n/n, 50% n/GBED
n/GBED x n/GBED gives 25% n/n, 50% n/GBED, 25% GBED/GBED

Affected foals never reach breeding age, so in practice no mating involves a GBED/GBED parent.

Forebyggelse

There is no treatment, 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.

An affected foal. Nothing changes the outcome. Your veterinarian guides supportive care and welfare decisions.

Resultater

DNA-testen verificerer tilstedeværelsen af derecessive GBED-allelerog præsenterer resultater som et af følgende:

N/- Negativfor GBED. Fravær af det defekte allel, der er ansvarlig for GBED.
GBED/N- Bærer - Positiv heterozygot for GBED. Tilstedeværelse af én kopi af det allel, der er ansvarlig for GBED. Hesten er bærer af GBED og kan videregive en kopi af GBED-allelet til sit afkom ved avl.
GBED/ -Rammet - Positiv homozygot for GBED. Tilstedeværelse af to kopier af det allel, der er ansvarlig for GBED. Dyret er ramt af GBED-lidelsen. GBED er dødelig og forårsager abort og/eller neonatal dødelighed.

Krav til prøver

30 til 40 - hårrødder - kuvert eller 5 ml - blod - K3 EDTA-glas

Behandlingstid

2 til 5 hverdage

Sådan fungerer det

🛒 Koop de test: kies de test en koop hem online.

📧 Ontvang de instructies: na bevestiging van de betaling ontvangt u de instructies voor het afnemen van het monster per e-mail.

📄 Vul het formulier in: print het inzendformulier en vul het in met de identificatie van het dier.

✨ Neem het monster af: trek 20 tot 40 haren met wortel (bulbus) uit en plak ze in het gemarkeerde vak op het formulier, of laat uw dierenarts bloed afnemen in een K3-EDTA-buis.

📮 Stuur het naar het laboratorium: Equigerminal, S.A., HIESE, Rua da Quinta do Sobreiro, 25, Quinta Vale do Espinhal, 3230-343 Penela, PORTUGAL.

📊 Ontvang het rapport: het gecertificeerde rapport wordt uitgegeven zodra de analyse is gevalideerd.

Ofte stillede spørgsmål

Hvad er GBED?

GBED (Glycogen Branching Enzyme Deficiency) er en dødelig, arvelig sygdom, der forhindrer normal glykogenlagring, hvilket fører til alvorlig energimangel.

Kan bærerheste udvikle sygdommen?

Nej. Bærerheste (N/GBED) er klinisk sunde, men kan videregive mutationen til deres afkom.

Hvordan arves GBED?

GBED følger et autosomalt recessivtarvemønster. Et ramt føl skal arve en muteret kopi fra hver forælder.

Hvilke racer skal testes?

Test anbefales stærkt for Quarter Horses, Paint Horsesog beslægtede racer på grund af den relativt høje bærerfrekvens.

Hvorfor skal opdrættere udføre denne test?

DNA-test identificerer bærere før avl, hvilket giver mulighed for informerede parringsbeslutninger, der forhindrer aborter og fødslen af ramte føl, samtidig med at værdifulde blodlinjer bevares.

For Professionals

Genetic and clinical detail for veterinarians, geneticists and laboratories.

Gene / locus: GBE1 (1,4-alpha-glucan branching enzyme 1), ECA26.
Variant: c.102C>A, nonsense (premature stop codon), no functional enzyme. HGVS (EquCab3.0): NC_009169.3:g.8667651C>A; NM_001081940.2:c.102C>A; NP_001075409.1:p.(Tyr34*).
Alternative designations: Y34X; equine glycogen storage disease type IV (GSD IV), the same disease as GSD IV in humans. Laboratory allele symbol: GBED.
Variant identifiers: rs3437568674 (EVA); OMIA variant 322.
Variant classification: Pathogenic (P), ISAG/AVCG classification as listed in OMIA.
Mechanism: without branching enzyme, glycogen cannot be packed into its branched storage form; an abnormal, poorly branched polysaccharide that cannot be broken down accumulates in skeletal muscle, heart, liver and brain.
Inheritance: autosomal recessive, lethal; pedigree and genotype data consistent with a single founder (Wagner et al., 2006). OMIA code: A (autosomal).
Penetrance / expressivity: homozygotes: abortion, stillbirth or neonatal death. About 2.5% of aborted and neonatal foals of Quarter Horse-related breeds submitted to two US diagnostic laboratories were homozygous, most of them abortions; characteristic deposits were found retrospectively in 8 of 9 affected foals (Wagner et al., 2006). In the first published series, related Quarter Horse foals all died by 7 weeks: stillbirth, transient flexural deformities, seizures, respiratory or cardiac failure, or persistent recumbency (Valberg et al., 2001).
Breeds with documented carriers or cases: Quarter Horse and American Paint Horse (OMIA variant record); Quarter Horse-related breeds and crosses, including Appendix Quarter Horses; confirmed in Brazilian Quarter Horses (Araujo et al., 2018). Not found in 227 Thoroughbreds (Wagner et al., 2006). Appaloosas and Ponies of the Americas are often tested because of Quarter Horse ancestry, but no confirmed carrier is known in a published study.
Allele / carrier frequencies: carrier frequency 8.3% of 338 Quarter Horses, 7.1% of 197 Paint Horses, 0% of 227 Thoroughbreds (Wagner et al., 2006). Allele frequency 5.4% in 200 control Quarter Horses and 13.2% in western pleasure horses (Tryon et al., 2009). Carrier frequency 7.94% of 742 Brazilian Quarter Horses competing in cutting, halter, racing, reining and barrel racing (Araujo et al., 2018). Allele frequency 10.9% in elite reining Quarter Horses, unchanged 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: consider GBED in abortion, stillbirth or weak neonates of Quarter Horse and Paint lineage. Abnormal polysaccharide deposits in cardiac muscle, skeletal muscle and liver are easily missed unless periodic acid-Schiff (PAS) staining is used; the heart is the most reliable site, but at least one confirmed affected foal showed no deposits. Erythrocyte branching-enzyme activity (about half-normal in carriers) gave only an indication and has been superseded by DNA testing.

Key references:

Ward TL, Valberg SJ, Adelson DL, Abbey CA, Binns MM, Mickelson JR (2004). Glycogen branching enzyme (GBE1) mutation causing equine glycogen storage disease IV. Mamm Genome 15:570-577. PMID 15366377.
Valberg SJ, Ward TL, Rush B, Kinde H, Hiraragi H, Nahey D, Fyfe J, Mickelson JR (2001). Glycogen branching enzyme deficiency in Quarter Horse foals. J Vet Intern Med 15:572-580.
Ward TL, Valberg SJ, Lear TL, Guerin G, Milenkovic D, Swinburne JE, et al. (2003). Genetic mapping of GBE1 and its association with glycogen storage disease IV in American Quarter horses. Cytogenet Genome Res 102:201-206. doi:10.1159/000075749.
Wagner ML, Valberg SJ, Ames EG, Bauer MM, Wiseman JA, Penedo MCT, Kinde H, Abbitt B, Mickelson JR (2006). Allele frequency and likely impact of the glycogen branching enzyme deficiency gene in Quarter Horse and Paint Horse populations. J Vet Intern Med 20:1207-1211.
Tryon RC, Penedo MCT, McCue ME, et al. (2009). Evaluation of allele frequencies of inherited disease genes in subgroups of American Quarter Horses. J Am Vet Med Assoc 234:120-125. doi:10.2460/javma.234.1.120.
Araujo CET, Delfiol DJZ, Badial PR, Oliveira-Filho JP, Araujo-Junior JP, Borges AS (2018). Prevalence of the glycogen branching enzyme deficiency mutation in Quarter Horses in Brazil. J Equine Vet Sci 62:81-84. doi:10.1016/j.jevs.2017.10.010.
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.