Glycogen branching enzyme deficiency " "(GBED) ""in Appaloosa, Paint Horse and Quarter Horse

Glycogen Branching Enzyme Deficiency (GBED)


Affected foals lack the enzyme GBE that is necessary for synthesis and storage of glycogen. Predominantly affected are sceletal muscle, brain and heart. Clinical signs associated with GBED are:
-Abortion, dead or weak foals
-sudden death due to heart failure and or seizures
-tachypnoa due to weak sceletal muscle (diaphragm)
-generalised weakness, especially when getting up
There is no treatment available yet and up to now affected foals died or had to be euthanized.
Until recently GBED has not been recognized as a disease, mainly because the clinical signs are very similar to other diseases that typically affect foals. Furthermore, routine staining of muscle tissue post mortem was not suitable to detect GBED.
After the development of a genetic test to identify the mutation responsible for GBED, epidemiological studies revealed that about 10% of the horses belonging to QH, Paints and related blood lines carry the mutation. It is suspected that about 3% of the abortions of QH are due to this disease.


Quarter Horses, Paint Horses, Appaloosas and related breed

Trait of inheritance


Test duration

3-5 days after arrival of the sample in the lab


The DNA test is performed out of EDTA blood or or 20-30 hair roots from mane or tail. Test kits can be ordered free of charge. (order-form). If hair is sent in, possibly the genetic material is not sufficient to run the test. In this case it would be best to send in an EDTA blood sample.

Testing procedure

Please send in your sample together with the lab order genetic. Results will be transmitted optionally via post, fax or email. After completion of the test you will receive a separate invoice. Payment can be made via credit card or bank transfer.
Breeding club discounts apply if a copy of the membership card is sent together with the respective samples. Due to administrative reasons the invoiced price can not be altered subsequently.


Please contact our molecular biology team for further questions.

Steubenstraße 4
D-97688 Bad Kissingen

Telefon: +49 (0)971 72020
Fax: +49 (0)971 68546


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