Risk of scrapie in British sheep of different prion protein genotype
Risk of scrapie in British sheep of different prion protein genotype
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DOI：
10.1099/vir.0.79876-0
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发表时间：
2004-09-01
影响因子：
3.8
通讯作者：
Gravenor, MB
中科院分区：
文献类型：
--
作者：
Baylis, M;Chihota, C;Gravenor, MB
绵羊PrP基因与瘙痒病死亡风险之间存在着广泛的相关性。某些基因类型显然与疾病的易感性有关，而其他的与抗药性有关。然而，还没有试图量化所有15种PrP基因型的疾病风险。这里，将近14 000只英国绵羊的PrP基因分型和1500多个确诊的瘙痒病病例组合在一起，得出了英国绵羊的瘙痒病风险估计(该基因每百万只绵羊每年报告的病例数，或RCAM)，到目前为止，最大的瘙痒病风险从225到545 RCAM，是VRO编码的基因ARQ/VRO，ARH/VRQ和VRQ/VRQ。第二大风险(37RCAM)是ARQ/ARQ基因。ARR/ARR基因是唯一一种未报告瘙痒病病例的有数字意义的基因型别。Ahq/VRQ绵羊的aho等位基因具有抵抗力，患瘙痒病的风险很低(0.7RCAM)，而ahq纯合子(5RCAM)的风险较高和中等。当用VRQ编码时，ARH等位基因似乎表现出易感性，但当与其他等位基因编码时，则可能产生抗性。瘙痒的风险随年龄而变化：VRQ/VRQ和ARH/VRQ的风险在2岁时达到峰值，ARQ/VRQ的风险在3岁时达到峰值。有一些证据表明，在4年和5年的风险较低之后，大约6年的风险出现了第二次上升。与其他已公布数据的比较表明，某些PrP基因型的瘙痒病风险在英国和其他国家可能不同。
There is a well-established association between sheep prion protein (PrP) genotype and the risk of death from scrapie. Certain genotypes are clearly associated with susceptibility to the disease and others to resistance. However, there have been no attempts to quantify the disease risk for all 15 PrP genotypes. Here, clatasets of the PrP genotypes of nearly 14 000 British sheep and of more than 1500 confirmed scrapie cases were combined to yield an estimate of scrapie risk (reported cases per annum per million sheep of the genotype, or RCAM) for British sheep, The greatest scrapie risk by far, ranging from 225 to 545 RCAM, was for the VRO-encoding genotypes ARQ/VRO, ARH/VRQ and VRQ/VRQ. The next greatest risk (37 RCAM) was for the ARQ/ARQ genotype. The ARR/ARR genotype was the only numerically significant genotype for which no scrapie cases have been reported. The AHO allele conferred resistance and the risk of scrapie in AHQ/VRQ sheep was very low (0.7 RCAM), although there was a higher and moderate risk for the AHQ homozygote (5 RCAM). The ARH allele appeared to confer susceptibility when encoded with VRQ, but possible resistance when encoded with other alleles. Scrapie risk varied with age: for VRQ/VRQ and ARH/VRQ the risk peaked at 2 years of age; that for ARQ/VRQ peaked at 3 years. There was some evidence that, following the lower risk at 4 and 5 years, a second rise occurred from about 6 years. Comparison with other published data indicated that the scrapie risk of certain PrP genotypes may differ between Great Britain and other countries.