Product Information
| Affected breeds: | New Forest Pony and related breeds |
| Test #: | H109 |
| Description: | Congenital Myotonia Genetic Testing This test detects the single basepair change in exon 15 in the CLCN1 gene. |
| Samples: | Hair, blood |
| Time: | 10 – 14 days |
Congenital Myotonia (CM)
35,00 €
excl. 19% VAT
→ Impaired movement due to muscle rigidity.
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 “Aditional Info”).
General Information
- Foal may seem healthy when born but symptoms may evolve and worsen over time.
- Symptoms mentioned in the “Symptoms” tap are caused by the general muscle stiffness in the affected horse.
Symptoms
- Difficulties rising
- Gait abnormalities
- Muscular rigidity, especially in hindquarters
- Vertigo and 0ccasional falling
- Impaired flexibility of fetlock joints
- Temporary protruding third eyelid
- Inward protuberant eyeballs
- Excessively muscled
Inheritance and Genotypes
→ CM is an autosomal recessive hereditary disease, meaning that horses with only one copy of the genetic variant (N/cm) are clinically normal carriers while horses with two copies of the genetic variant (cm/cm) are affected.
| Genotype: | The horse is: | Effects: |
| N/N | normal. | The horse does not have any copies of the genetic variant causative for CM and therefore cannot pass it on to any offspring. |
| N/cm | a carrier. | The horse is clinically healthy. It has one copy of the genetic variant causitive for CM, which will be passed on to its offspring with a probability of 50%. |
| cm/cm | affected. | The genetic variant causative for CM will be passed on to all offspring. All offspring will be carriers (N/cm). |
Recommendations
- Carriers may be bred to normal animals (N/cm 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/cm x N/cm) is not recommended due to the possibility of 25% of the offspring being affected.
- Affected animals (cm/cm) should not be used for breeding.
References
Wijnberg, I.D., Owczarek-Lipska, M., Sacchetto, R., Mascarello, F., Pascoli, F., Grünberg, W., van der Kolk, J.H., Drögemüller, C.: A missense mutation in the skeletal muscle chloride channel 1 (CLCN1) as candidate causal mutation for congenital myotonia in a New Forest pony. Neuromuscul Disord 22:361-7, 2012. Pubmed reference: 22197188. Doi: 10.1016/j.nmd.2011.10.001.
Further information is available at Online Mendelian Inheritance in Animals.
