The unique appearance of Scottish Fold cats is caused by a single gene variant in TRPV4, which impacts the development of cartilage. This results in the ears folding forward and variable effects on articular cartilage and bone. While some find this appearance desirable, early work demonstrated that homozygous cats with two copies of this variant develop severe radiographic consequences. Subsequent breeding programs have mated heterozygous cats with straight-eared cats to ensure an equal mix of heterozygous (fold) and wild-type (nonfolded) offspring, in the hope of raising healthy cats. More recent radiological surveys suggest that these heterozygous cats may also have medical problems consisting of deformed distal extremities in the worst cases and accelerated onset of osteoarthritis. However, these previous studies were undermined by selection biases, lack of controls, unblinded assessment and lack of known genotypes. Our aim was to determine if heterozygous cats exhibit radiological abnormalities when controlling for these limitations. Specifically, DNA and radiographs were acquired for 22 Scottish Fold cats. Four reviewers, blinded to the ear phenotype, assessed the lateral radiographs. Genotyping showed that all 10 folded-ear cats were heterozygous, and none of the straight-ear cats (n = 12) had the abnormal TRPV4 variant. Although each reviewer, on average, gave a numerically worse ‘severity score’ to folded-ear cats relative to straight-ear cats, the images in heterozygous cats showed much milder radiological signs than previously published. This study provides additional information to be considered in the complicated debate as to whether cats with the TRPV4 variant should be bred for folded ears given the potential comorbidities.

苏格兰折耳猫的独特外观是由TRPV4 中的单个基因变异引起的，这会影响软骨的发育。这导致耳朵向前折叠并对关节软骨和骨骼产生不同的影响。虽然有些人认为这种外观是可取的，但早期的工作表明，具有这种变体的两个副本的纯合猫会产生严重的放射学后果。随后的育种计划将杂合子猫与直耳猫交配，以确保杂合子（折叠）和野生型（非折叠）后代的混合均匀，以期养出健康的猫。最近的放射学调查表明，这些杂合子猫也可能存在医疗问题，包括在最坏的情况下四肢畸形和骨关节炎的加速发作。然而，这些先前的研究因选择偏差、缺乏对照、非盲法评估和缺乏已知基因型而受到破坏。我们的目的是确定杂合子猫在控制这些限制时是否表现出放射学异常。具体来说，采集了 22 只苏格兰折耳猫的 DNA 和 X 光片。四位对耳朵表型不知情的审阅者评估了侧位 X 光片。基因分型显示，所有 10 只折耳猫都是杂合子，而直耳猫中没有一只（n  = 12) 有异常的TRPV4变体。尽管平均而言，每位评论者对折耳猫的“严重程度评分”比直耳猫更差，但杂合猫的图像显示出的放射学迹象比以前发表的要轻得多。这项研究提供了在复杂的辩论中需要考虑的额外信息，即考虑到潜在的合并症，是否应该为折叠耳朵饲养带有TRPV4变体的猫。