Product Information
| Affected breeds: | Friesians and related breeds |
| Test #: | H119 |
| Description: | Friesian Dwarfism Genetic Testing This test detects the single basepair change in the B4GALT7 gene. |
| Samples: | Hair, blood |
| Time: | 10 – 14 days |
Friesian Dwarfism
Regular Price: 35,00 € Special Price: 30,00 €
excl. 19% VAT
→ Dwarfism in the Friesian breed with disproportionate limbs.
Instructions for ordering:
- Enter the information of the first horse for which you want to order the test
- Add to cart
- Go to cart to check out, or
- Enter the information for a second horse
- For sample collection follow the instructions here.
- You can use this template to send in hair samples.
- Please also send the completed order form together with the samples.
For a breeder or veterinarian discount please contact us before ordering.
Any information you include here is optional, but will be included on the certificate of results (except “Additional Info”).
General Information
- Abnormal development of leg bones and rib cage.
- Affected horses have a normal sized head and torso but disproportionately short legs.
- Rib cage shows inward protrusion of ribs which may lead to breathing issues.
- Tendon laxity leads to instable joints and hence to abnormal gait.
Symptoms
- Short legs in comparison to a normal sized head and torso
- Inward protruded rib cage
- Hyperextension of fetlock joints
- Tendon laxity
- Abnormal gait with outward rotation
Inheritance and Genotypes
→ Friesian Dwarfism is an autosomal recessive hereditary disease, meaning that horses with only one copy of the genetic variant (N/fd) are clinically normal carriers while horses with two copies of the genetic variant (fd/fd) are affected.
| Genotype: | The horse is: | Effects: |
| N/N | normal. | The horse does not have any copies of the genetic variant causative for Friesian Dwarfism and therefore cannot pass it on to any offspring. |
| N/fd | a carrier. | The horse is clinically healthy. It has one copy of the genetic variant causitive for Friesian Dwarfism, which will be passed on to its offspring with a probability of 50%. |
| fd/fd | affected. | The horse has two copies of the genetic variant causitive for Friesian Dwarfism. The variant will be passed on to all offspring. All offspring will be carriers (N/fd). |
Recommendations
- Carriers may be bred to normal animals (N/fd x N/N) without any risk of producing affected offspring. The offspring should also be tested before breeding to determine if they are carriers or normal.
- Breeding two carriers (N/fd x N/fd) is not recommended due to the possibility of 25% of the offspring being affected.
- Affected animals (fd/fd) should not be used for breeding.
References
Leegwater, P.A., Vos-Loohuis, M., Ducro, B.J., Boegheim, I.J., van Steenbeek, F.G., Nijman, I.J., Monroe, G.R., Bastiaansen, J.W., Dibbits, B.W., van de Goor, L.H., Hellinga, I., Back, W., Schurink, A. : Dwarfism with joint laxity in Friesian horses is associated with a splice site mutation in B4GALT7. BMC Genomics 17:839, 2016. Pubmed reference: 27793082. DOI: 10.1186/s12864-016-3186-0.
Further information is available Online Mendelian Inheritance in Animals.
