Munchkin cats were founded on a naturally occurring mutation segregating into long-legged and short-legged types. Short-legged cats showed disproportionate dwarfism (chondrodysplasia) in which all four legs are short and are referred as standard Munchkin cats. Long-legged animals are referred as non-standard Munchkin cats. A previous study using genome-wide single nucleotide polymorphisms (SNPs) for genome-wide association analysis identified a significantly associated region at 168–184 Mb on feline chromosome (FCA) B1. In this study, we validated the critical region on FCA B1 using a case-control study with 89 cats and 14 FCA B1-SNPs. A structural variant within UGDH (NC_018726.2:g.173294289_173297592delins108, Felis catus 8.0, equivalent to NC_018726.3:g.174882895_174886198delins108, Felis catus 9.0) on FCA B1 was perfectly associated with the phenotype of short-legged standard Munchkin cats. This UGDH structural variant very likely causes the chondrodysplastic (standard) phenotype in Munchkin cats. The lack of homozygous mutant phenotypes and reduced litter sizes in standard Munchkin cats suggest an autosomal recessive lethal trait in the homozygote state. We propose an autosomal dominant mode of inheritance for the chondrodysplastic condition in Munchkin cats.

中文翻译：

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一种与标准Munchkin猫有关的UGDH结构变体。

蒙奇金猫是建立在自然发生的突变上，分为长腿和短腿两种类型。短腿猫表现出不相称的侏儒症（软骨发育不良），其中所有四只腿都很短，被称为标准蒙克金猫。长腿动物被称为非标准Munchkin猫。先前使用全基因组单核苷酸多态性（SNP）进行全基因组关联分析的研究确定了猫染色体（FCA）B1上168-184 Mb的显着相关区域。在这项研究中，我们通过对89只猫和14只FCA B1-SNP进行病例对照研究，验证了FCA B1的关键区域。UGDH（NC_018726.2：g.173294289_173297592delins108，Felis catus 8.0）中的结构变体，等效于NC_018726.3：g.174882895_174886198delins108，Felis catus 9。0）在FCA上，B1与短腿标准Munchkin猫的表型完美相关。这种UGDH结构变异很可能引起Munchkin猫的软骨发育不良（标准）表型。标准Munchkin猫缺乏纯合突变体表型和产仔数减少，表明在纯合子状态下常染色体隐性致死性状。我们提出了一种Munchkin猫软骨发育异常的常染色体显性遗传方式。