Dranchak Patricia K, Valberg Stephanie J, Onan Gary W, Gallant Esther M, MacLeay Jennifer M, McKenzie Erica C, De La Corte Flavio D, Ekenstedt Kari, Mickelson James R
Department of Veterinary Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108, USA.
J Am Vet Med Assoc. 2005 Sep 1;227(5):762-7. doi: 10.2460/javma.2005.227.762.
To develop a diagnostic test for recurrent exertional rhabdomyolysis (RER) in Thoroughbreds that relied on in vitro contracture of muscle biopsy specimens and determine whether the inheritance pattern of RER diagnosed on the basis of this contracture test was consistent with an autosomal dominant trait.
Clinical trial.
8 adult horses with RER and 16 control adult horses for development of the contracture test; 23 foals for inheritance of RER.
External intercostal muscle biopsy specimens from the 24 adult horses were tested for contracture in response to halothane and caffeine, and criteria for a positive test result were determined. These criteria were then applied to results for the 23 foals to determine whether they had RER. Simple segregation analysis was performed to determine whether results were consistent with a dominant pattern of inheritance.
Results of the contracture test were positive for 5 of the 12 colts and 4 of the 11 fillies. Results of segregation analysis were consistent with an auto-. somal dominant pattern of inheritance. Two sires with RER produced colts with RER, supporting the hypothesis that RER had an autosomal, rather than an X-linked, inheritance pattern. In addition, in 1 instance, an unaffected colt was produced by 2 affected parents, which was not consistent with a recessive mode of inheritance.
Although the expression of the RER trait is influenced by sex, temperament, and diet, among other factors, results from the in vitro muscle contracture test and this breeding trial suggest that RER in Thoroughbreds can be modeled as a genetic trait with an autosomal dominant pattern of inheritance.
开发一种用于纯种马复发性运动性横纹肌溶解症（RER）的诊断测试，该测试依赖于肌肉活检标本的体外挛缩，并确定基于此挛缩测试诊断出的RER的遗传模式是否与常染色体显性性状一致。
临床试验。
8匹患有RER的成年马和16匹对照成年马用于挛缩测试的开发；23匹驹用于RER的遗传研究。
对24匹成年马的肋间外肌活检标本进行氟烷和咖啡因诱发的挛缩测试，并确定阳性测试结果的标准。然后将这些标准应用于23匹驹的测试结果，以确定它们是否患有RER。进行简单的分离分析以确定结果是否与显性遗传模式一致。
12匹雄驹中有5匹和11匹雌驹中有4匹的挛缩测试结果为阳性。分离分析结果与常染色体显性遗传模式一致。两匹患有RER的种马产下患有RER的雄驹，支持了RER具有常染色体而非X连锁遗传模式的假设。此外，在1例中，2匹患病亲本产下1匹未受影响的雄驹，这与隐性遗传模式不一致。
尽管RER性状的表达受性别、性情和饮食等多种因素影响，但体外肌肉挛缩测试和本次育种试验结果表明，纯种马的RER可被模拟为具有常染色体显性遗传模式的遗传性状。
