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HERDA (Hereditary Equine Regional Dermal Asthenia)
Test number: 8139
Gene: HERDA
Price: £ 48.00 (including VAT)
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Breeds
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Appaloosas
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Paint Horse
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Quarter Horse (Horse with quarter horse blood)
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The Disease |
Hereditary equine regional dermal asthenia (HERDA) is a degenerative genetic disease of the skin primarily found in the American QH. Within the population carrier frequency has been estimated between 1.8 and 6.5%; an autosomal recessive mode of inheritance is supported.
Affected foals rarely show symptoms at birth. Areas that develop symptoms later are focal and irregularly distributed over the body. However, most lesions are concentrated along the dorsal aspect. Since that the disease typically occurs by the age of 2 years when the horse first being broke to saddle. The horses skin is hyperextensible, scarred and often shows heavy lesions.
Histological examination only gives vague hints towards HERDA but cannot definitely diagnose the disease. |
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Description |
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The genetic defect leading to the disease has been identified. By DNA testing, the responsible mutation can be shown directly. This method provides a very high accuracy test and can be done at any age. It offers the possibility to distinguish not only between affected and clear horses, but also to identify clinically healthy carriers. This is an essential information for controlling the disease in the breed, as carriers are able to spread the disease in the population, but can not be identified by means of common laboratory diagnostic.
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Trait of Inheritance |
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HERDA follows autosomal recessive trait of inheritance
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Inheritance : AUTOSOMAL
RECESSIVE
trait
Sire
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Dam
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Offspring
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clear
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clear
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100% clear
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clear
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carrier
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50% clear + 50%
carriers
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clear
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affected
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100% carriers
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carrier
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clear
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50% clear + 50%
carriers
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carrier
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carrier
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25% clear + 25% affected
+ 50% carriers
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carrier
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affected
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50% carriers + 50%
affected
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affected
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clear
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100% carriers
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affected
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carrier
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50% carriers + 50%
affected
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affected
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affected
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100% affected
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Clear
Genotype: N / N [ Homozygous normal ]
The horse is noncarrier of the mutant gene.
It is very unlikely that the horse will develop HERDA (Hereditary Equine Regional Dermal Asthenia). The horse will never pass the mutation to its offspring, and therefore it can be bred to any other horse.
Carrier
Genotype: N / HERDA [ Heterozygous ]
The horse carries one copy of the mutant gene and one
copy of the normal gene.
It is very unlikely that the horse will develop HERDA (Hereditary Equine Regional Dermal Asthenia) but since it carries the mutant gene, it can pass it on to its offspring with the probability of 50%. Carriers should only be bred to clear horses. Avoid breeding carrier to carrier because 25% of their offspring is expected to be affected (see table above)
Affected
Genotype: HERDA / HERDA [ Homozygous mutant ]
The horse carries two copies of the mutant gene and
therefore it will pass the mutant gene to its entire offspring.
The horse is likely to develop HERDA (Hereditary Equine Regional Dermal Asthenia) and will pass the mutant gene to its entire offspring
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Sample Requirements |
Hair Sample from mane with roots (approx 30 hairs) or 1 ml whole blood in EDTA tube.
How to obtain a viable hair sample
Pull around 30 hairs from the mane of the horse with the roots (in faols hair from the tail maybe taken). Wrap the hairs around your finger or a comb, as close as possible to the skin to ensure you obtain the hair roots. Keep dry, put in a bag, label the bag with the horse name, test (s) required. Place in an envelope and send back to us together with the order form. Broken or cut off hair will not be accepted.
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Price
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£ 48.00 (including VAT)
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| See also: |
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