Glycogen branching enzyme deficiency 1766429 221845430 2008-06-26T10:26:35Z Cydebot 1215485 Robot - Moving category Quarter Horses to American Quarter Horses per [[WP:CFD|CFD]] at [[Wikipedia:Categories for discussion/Log/2008 June 16]]. [[Image:Bockhufe.jpg|right|thumb|220px|Contracted tendons is a common symptom of foals with GBED]] '''Glycogen Branching Enzyme Deficiency''' ('''GBED''') is a [[genetic disease]] affecting [[horse]]s, especially [[American Quarter Horse]]s and related breeds. ==Diagnosis, Symptoms, and Prognosis== Lacking an enzyme necessary for storing [[glycogen]], the horse's brain, heart muscle, and skeletal muscles cannot function, leading to rapid death. This condition may be diagnosed with a muscle biopsy. Most foals with GBED are aborted or stillborn, and those that survive live only for a few months. Symptoms include general weakness, contracted tendons, seizures, cardiac arrest, and sudden death. There is no known treatment. ==Causes== The disease occurs in foals who are [[homozygous]] for the lethal GBED allele, meaning both parents must be [[heterozygous]] for the allele. A [[blood test]] for this allele was developed by the [[University of Minnesota]] College of Veterinary Medicine and [[as of 2005]] is licensed to the [[UC Davis]] Veterinary Genetics Laboratory. Using this, breeders can avoid crosses that could produce GBED foals, and eventually [[selective breeding|selectively breed]] it out. Initial samples suggest that about 10% of Quarter Horses are carriers. This genetic disease has been linked to the foundation sire King. == See also == [[Glycogen storage disease type IV]] == External links == * [http://www.cvm.umn.edu/umec/lab/gbed.html University of Minnesota: Neuromuscular Diagonistic Laboratory: Glycogen Branching Enzyme Deficiency (GBED)] * [http://www.vgl.ucdavis.edu/service/horse/GBED.html UC Davis: Veterinary Genetics Laboratory: Glycogen Branching Enzyme Deficiency (GBED)] * [http://www.vetgen.com/equine-gbed-service.html VetGen: Veterinary Genetics Services: Glycogen Branching Enzyme Deficiency (GBED)] ==Sources== "Testing for Genetic Diseases." ''Equus 353''. pp 40-41. [[Category:Horse diseases]] [[Category:American Quarter Horses]]