MacLeay J M, Valberg S J, Sorum S A, Sorum M D, Kassube T, Santschi E M, Mickelson J R, Geyer C J
Department of Clinical and Population Sciences, College of Veterinary Medicine, University of Minnesota, St Paul 55108, USA.
Am J Vet Res. 1999 Feb;60(2):250-6.
To determine the likely mode of inheritance and identify probable foundation horses for recurrent exertional rhabdomyolysis (RER) in Thoroughbred (TB) racehorses.
4 families of TB racehorses with a high prevalence of RER, consisting of 3 to 53 horses/family, were used to determine mode of inheritance. Sixty-two TB horses with RER and 34 control TB racehorses without RER were used to identify probable foundation horses for the RER trait.
RER was diagnosed by a veterinarian and verified by detecting high serum creatine kinase activity. Pedigrees dating from 1930 for all horses were entered into a database. Pedigrees of horses in 4 families were visually inspected for a pattern of inheritance and used for calculation of foundation horse contributions and inbreeding coefficients. The Markov chain Monte Carlo technique was used to analyze pedigrees of the 62 affected and 34 control horses for the conditional probability of foundation genotypes. A dominant mode of inheritance with variable expression model was used.
Pedigree analysis supported an autosomal dominant mode of inheritance with variable expression. All affected horses from the 4 families shared a common ancestor. This ancestor and 5 other stallions had a conditional probability of 1.00 for being affected. All 6 stallions shared a common male ancestor within 3 to 5 generations.
On the basis of this study, the RER trait has been in TB racehorses for more than 70 years and may be inherited as an autosomal dominant trait with variable expression.
确定纯种赛马反复运动性横纹肌溶解症（RER）可能的遗传模式，并识别可能的基础种马。
使用4个RER高发的纯种赛马家族，每个家族有3至53匹马，以确定遗传模式。62匹患有RER的纯种马和34匹无RER的对照纯种赛马用于识别RER性状的可能基础种马。
由兽医诊断RER，并通过检测高血清肌酸激酶活性进行验证。将所有马匹可追溯至1930年的系谱录入数据库。对4个家族中马匹的系谱进行直观检查以寻找遗传模式，并用于计算基础种马的贡献和近亲繁殖系数。采用马尔可夫链蒙特卡罗技术分析62匹患病马和34匹对照马的系谱，以确定基础基因型的条件概率。使用具有可变表达模型的显性遗传模式。
系谱分析支持具有可变表达的常染色体显性遗传模式。4个家族中所有患病马都有一个共同祖先。这个祖先和其他5匹种马患RER的条件概率为1.00。所有6匹种马在3至5代内有一个共同的雄性祖先。
基于本研究，RER性状在纯种赛马中已存在70多年，可能作为一种具有可变表达的常染色体显性性状遗传。
