Aleman M, Nieto J E, Magdesian K G
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Tupper Hall 2108, One Shields Avenue, Davis, CA 95616, USA.
J Vet Intern Med. 2009 Mar-Apr;23(2):329-34. doi: 10.1111/j.1939-1676.2009.0274.x. Epub 2009 Feb 11.
Anesthetic-induced malignant hyperthermia (MH) has been documented in Quarter Horses with a single point mutation in the ryanodine receptor 1 gene (RyR1) at nucleotide C7360G, generating a R2454G amino acid substitution. However, there have been no reports of nonanesthetic manifestations of MH in horses with the C7360G mutation.
To describe clinical manifestations of Quarter Horses with the C7360G mutation.
Eleven Quarter Horses with the RyR1 C7360G mutation.
This prospective study included horses with suspected MH, undetermined etiology of sudden death, death within hours of onset of rhabdomyolysis, muscle rigidity, stiffness, intermittent sweating, and persistent increases in serum muscle enzyme activities. Whole blood in EDTA and skeletal muscle were processed for genetic and histochemical analysis. Medical records and pedigrees were collected when available.
Both anesthetic- and non-anesthetic-associated myopathic manifestations of MH occurred in halter Quarter Horses with mutation of RyR1. The disease is inherited as an autosomal dominant trait. Clinical and laboratory abnormalities were similar in both forms. Rhabdomyolysis was a common finding in both groups of horses. Skeletal muscle histochemical findings were nonspecific and compatible with a noninflammatory myopathic process.
MH is a potentially fatal disease of Quarter Horses that could be triggered by halogenated anesthetics and other nonanesthetic factors that may include exercise, stress, breeding, illnesses, and concurrent myopathies.
已证实 Quarter 马中存在麻醉诱导的恶性高热（MH），其兰尼碱受体 1 基因（RyR1）在核苷酸 C7360G 处发生单点突变，产生 R2454G 氨基酸替代。然而，尚无关于携带 C7360G 突变的马匹出现 MH 非麻醉表现的报道。
描述携带 C7360G 突变的 Quarter 马的临床表现。
11 匹携带 RyR1 C7360G 突变的 Quarter 马。
这项前瞻性研究纳入了疑似 MH、猝死病因不明、横纹肌溶解症发作数小时内死亡、肌肉僵硬、强直、间歇性出汗以及血清肌肉酶活性持续升高的马匹。采集 EDTA 抗凝血和骨骼肌进行基因和组织化学分析。如有可用信息，收集病历和系谱。
携带 RyR1 突变的挽用 Quarter 马出现了与麻醉和非麻醉相关的 MH 肌病表现。该疾病以常染色体显性性状遗传。两种形式的临床和实验室异常情况相似。横纹肌溶解症在两组马匹中均为常见表现。骨骼肌组织化学检查结果无特异性，与非炎性肌病过程相符。
MH 是 Quarter 马的一种潜在致命疾病，可由卤化麻醉剂及其他非麻醉因素触发，这些因素可能包括运动、应激、繁殖、疾病及并发的肌病。
