{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,21]],"date-time":"2026-02-21T12:11:57Z","timestamp":1771675917276,"version":"3.50.1"},"reference-count":16,"publisher":"American Veterinary Medical Association (AVMA)","issue":"11","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["ajvr"],"published-print":{"date-parts":[[2017,11]]},"abstract":"<jats:title>Abstract<\/jats:title>\n<jats:p><jats:bold>OBJECTIVE<\/jats:bold> To characterize clinical findings for polysaccharide storage myopathy (PSSM) in warmblood horses with type 1 PSSM (PSSM1; caused by mutation of the glycogen synthase 1 gene) and type 2 PSSM (PSSM2; unknown etiology).<\/jats:p>\n<jats:p><jats:bold>SAMPLE<\/jats:bold> Database with 3,615 clinical muscle biopsy submissions.<\/jats:p>\n<jats:p><jats:bold>PROCEDURES<\/jats:bold> Reported clinical signs and serum creatine kinase (CK) and aspartate aminotransferase (AST) activities were retrospectively analyzed for horses with PSSM1 (16 warmblood and 430 nonwarmblood), horses with PSSM2 (188 warmblood and 646 nonwarmblood), and warmblood horses without PSSM (278). Lameness examinations were reviewed for 9 warmblood horses with PSSM2. Muscle glycogen concentrations were evaluated for horses with PSSM1 (14 warmblood and 6 nonwarmblood), warmblood horses with PSSM2 (13), and horses without PSSM (10 warmblood and 6 nonwarmblood).<\/jats:p>\n<jats:p><jats:bold>RESULTS<\/jats:bold> Rhabdomyolysis was more common for horses with PSSM1 (12\/16 [75%] warmblood and 223\/303 [74%] nonwarmblood) and nonwarmblood horses with PSSM2 (221\/436 [51%]) than for warmblood horses with PSSM2 (39\/147 [27%]). Gait abnormality was more common in warmblood horses with PSSM2 (97\/147 [66%]) than in warmblood horses with PSSM1 (1\/16 [7%]), nonwarmblood horses with PSSM2 (176\/436 [40%]), and warmblood horses without PSSM (106\/200 [53%]). Activities of CK and AST were similar in warmblood horses with and without PSSM2. Muscle glycogen concentrations in warmblood and nonwarmblood horses with PSSM1 were significantly higher than concentrations in warmblood horses with PSSM2.<\/jats:p>\n<jats:p><jats:bold>CONCLUSIONS AND CLINICIAL RELEVANCE<\/jats:bold> Rhabdomyolysis and elevated muscle glycogen concentration were detected in horses with PSSM1 regardless of breed. Most warmblood horses with PSSM2 had stiffness and gait abnormalities with CK and AST activities and muscle glycogen concentrations within reference limits.<\/jats:p>","DOI":"10.2460\/ajvr.78.11.1305","type":"journal-article","created":{"date-parts":[[2017,10,27]],"date-time":"2017-10-27T12:27:46Z","timestamp":1509107266000},"page":"1305-1312","source":"Crossref","is-referenced-by-count":18,"title":["Clinical characteristics and muscle glycogen concentrations in warmblood horses with polysaccharide storage myopathy"],"prefix":"10.2460","volume":"78","author":[{"given":"Susannah S.","family":"Lewis","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anne M.","family":"Nicholson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zo\u00eb J.","family":"Williams","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stephanie J.","family":"Valberg","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1272","reference":[{"key":"ref1","series-title":"Equine Vet J","doi-asserted-by":"publisher","first-page":"171","DOI":"10.2746\/042516408X244262","article-title":"An epidemiological study of myopathies in warmblood horses","volume":"40","author":"Hunt","year":"2008"},{"key":"ref2","series-title":"Vet J","doi-asserted-by":"publisher","first-page":"330","DOI":"10.1016\/j.tvjl.2008.01.008","article-title":"Prevalence of equine polysaccharide storage myopathy and other myopathies in two equine populations in the United Kingdom","volume":"180","author":"McGowan","year":"2009"},{"key":"ref3","series-title":"Equine Vet J","doi-asserted-by":"publisher","first-page":"597","DOI":"10.2746\/042516409X407611","article-title":"A glycogen synthase 1 mutation associated with equine polysaccharide storage myopathy and exertional rhabdomyolysis occurs in a variety of UK 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Res","doi-asserted-by":"publisher","first-page":"1319","DOI":"10.2460\/ajvr.2003.64.1319","article-title":"Epidemiologic characteristics and management of polysaccharide storage myopathy in Quarter Horses","volume":"64","author":"Firshman","year":"2003"},{"key":"ref15","series-title":"Equine Vet J","doi-asserted-by":"publisher","first-page":"548","DOI":"10.1111\/evj.12493","article-title":"Suspected myofibrillar myopathy in Arabian horses with a history of exertional rhabdomyolysis","volume":"48","author":"Valberg","year":"2016"},{"key":"ref16","series-title":"Brain","doi-asserted-by":"publisher","first-page":"439","DOI":"10.1093\/brain\/awh052","article-title":"Myofibrillar myopathy: clinical, morphological and genetic studies in 63 patients","volume":"127","author":"Selcen","year":"2004"}],"container-title":["American Journal of Veterinary 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