Thompson K G, Blair H T, Linney L E, West D M, Byrne T
Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.
N Z Vet J. 2005 Jun;53(3):208-12. doi: 10.1080/00480169.2005.36506.
A skeletal disease characterised by dwarfism, limb deformity and sometimes sudden death occurred over a period of 5 years in lambs born on a commercial sheep farm in Southland. The disease showed variable expression and occurred in crossbred sheep. A genetic aetiology was supported by the birth of affected lambs over two seasons in a flock of putative carrier and affected sheep transported to Massey University.
Affected lambs appeared normal at birth but showed evidence of dwarfism, wide-based stance and exercise intolerance as early as 1 week of age. Most died within the first 3 months of life, often after developing bilateral varus deformity of the forelimbs. Some severely-affected lambs died suddenly of respiratory embarrassment, probably due to tracheal collapse. Mildly-affected individuals had a short, blocky stature and some survived to breeding age.
Gross and microscopic lesions of variable severity were present in the tracheal, articular, epiphyseal and physeal cartilages. In severe cases, articular cartilage in major joints was eroded from weight-bearing surfaces. The trachea was flaccid, abnormally kinked, and had thickened cartilaginous rings and a narrow lumen. Affected sheep that survived to breeding age eventually developed severe degenerative joint disease. Histologically, chondrocytes were disorganised, surrounded by concentric rings of abnormal fibrillar material, and the matrix often contained focal to coalescing areas of chondrolysis.
Inherited chondrodysplasia of Texel sheep. CLINICAL RELEVANCE AND CONCLUSIONS: This chondrodysplasia differs from those previously described in sheep and is considered to be a newly-recognised, recessively-inherited genetic disease of the Texel breed. A defect in the synthesis of glycosaminoglycans in cartilage matrix is suspected. This disease of sheep may provide a suitable model for studying various forms of therapy for human chondrodysplasias.
在南岛一个商业养羊场出生的羔羊中，一种以侏儒症、肢体畸形且有时猝死为特征的骨骼疾病在5年时间里出现。该疾病表现出可变的症状，且发生在杂交绵羊身上。将一群假定的携带者和患病绵羊运到梅西大学后，两个季节均有患病羔羊出生，这支持了遗传病因学。
患病羔羊出生时看似正常，但早在1周龄时就表现出侏儒症、宽基站姿和运动不耐受的迹象。大多数在出生后的前3个月内死亡，常在出现前肢双侧内翻畸形后死亡。一些严重受影响的羔羊因呼吸窘迫突然死亡，可能是由于气管塌陷。轻度受影响的个体身材矮小且敦实，一些存活至繁殖年龄。
气管、关节、骨骺和生长板软骨存在严重程度不一的大体和微观病变。在严重病例中，主要关节的关节软骨从负重表面被侵蚀。气管松弛、异常扭结，软骨环增厚且管腔狭窄。存活至繁殖年龄的患病绵羊最终发展为严重的退行性关节疾病。组织学上，软骨细胞排列紊乱，被异常纤维状物质的同心环包围，基质中常含有局灶性至融合性的软骨溶解区域。
特克塞尔绵羊遗传性软骨发育不良。临床相关性及结论：这种软骨发育不良与先前在绵羊中描述的不同，被认为是特克塞尔品种新发现的隐性遗传疾病。怀疑软骨基质中糖胺聚糖的合成存在缺陷。绵羊的这种疾病可能为研究人类软骨发育不良的各种治疗方法提供合适的模型。
