Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano Emilia, BO, Italy; Institute of Genetics, Vetsuisse Faculty, University of Bern, Bremgartenstrasse109a, 3012 Bern, Switzerland.
National Association of Italian Beef-Cattle Breeders, Strada del Vio Viscioloso, 21, 06132 Perugia, Italy.
Animal. 2022 Jul;16(7):100569. doi: 10.1016/j.animal.2022.100569. Epub 2022 Jun 17.
In the last two decades, the molecular cause of six monogenic autosomal recessive disorders has been identified in native Italian beef cattle: two different ATP2A1 variants for the pseudomyotonia congenita, the first in Chianina and Romagnola (PMT1) and the second in Romagnola (PMT2); a KDM2B variant for the paunch calf syndrome (PCS) in Marchigiana and Romagnola; a NID1 variant for the congenital cataract (CC) in Romagnola; a LAMB1 variant for the hemifacial microsomia (HFM) in Romagnola; an ABCA12 variant for the ichthyosis fetalis (IF) in Chianina and a FA2H variant for the ichthyosis congenita (IC) in Chianina. The aim of this study was to evaluate the potential impact of these disorders in the affected Italian populations. For this purpose, 3331 Chianina, 2812 Marchigiana and 1680 Romagnola bulls born in the last 40 years were considered. The allelic frequency (AF) of the variant for PMT1 was 1.0% in Romagnola, 4.6% in Marchigiana and 5.9% in Chianina. The AF of the variant for PMT2 was 3.3% in Romagnola and 0% in the other two breeds. The AF of the variant for PCS was 11.7% in Romagnola, 2.0% in Marchigiana and 0% in Chianina. The AF of the variants for CC, HFM, IF and IC resulted below 3%, being the variants detected only in the breed populations in which they were previously reported. Considering a selected male population in the single breed, Chianina showed carrier prevalence of 11.9% for PMT1, 7.7% for IC and 6.4% for IF. Romagnola showed carrier prevalence of 23.4% for PCS, 6.7% for PMT2, 4.1% for HFM, 3.2% for CC and 2.0% for PMT1. Marchigiana showed carrier prevalence of 9.1% for PMT1 and 4.0% for PCS. With respect to the Romagnola cattle, the concerning presence of a total of five defect alleles in the population hampers a general approach based on the prevention of carriers from artificial insemination. However, identification of carriers may allow conscious mating to prevent the risk of homozygous descendants as well as the spread of heterozygous offspring. Therefore, systematic genotyping for all seven known harmful alleles is recommended to prevent risk mating between carriers, in particular to avoid the occurrence of affected offspring.
在过去的二十年中，已经确定了意大利本土肉牛中六种单基因常染色体隐性疾病的分子病因：两种不同的 ATP2A1 变体导致先天性假性肌强直，第一种存在于奇亚纳纳牛（Chianina）和罗曼纳拉牛（Romagnola）中（PMT1），第二种存在于罗曼纳拉牛（Romagnola）中（PMT2）；一种 KDM2B 变体导致腹部小牛综合征（PCS）在马尔凯（Marchigiana）和罗曼纳拉牛（Romagnola）中；一种 NID1 变体导致先天性白内障（CC）在罗曼纳拉牛（Romagnola）中；一种 LAMB1 变体导致颜面半侧短小畸形（HFM）在罗曼纳拉牛（Romagnola）中；一种 ABCA12 变体导致胎生鱼鳞病（IF）在奇亚纳纳牛（Chianina）中，一种 FA2H 变体导致先天性鱼鳞病（IC）在奇亚纳纳牛（Chianina）中。本研究旨在评估这些疾病在受影响的意大利人群中的潜在影响。为此，考虑了过去 40 年中出生的 3331 头奇亚纳纳牛（Chianina）、2812 头马尔凯（Marchigiana）和 1680 头罗曼纳拉牛（Romagnola）公牛。PMT1 变体的等位基因频率（AF）在罗曼纳拉牛（Romagnola）中为 1.0%，在马尔凯（Marchigiana）中为 4.6%，在奇亚纳纳牛（Chianina）中为 5.9%。PMT2 变体的 AF 在罗曼纳拉牛（Romagnola）中为 3.3%，在其他两个品种中为 0%。PCS 变体的 AF 在罗曼纳拉牛（Romagnola）中为 11.7%，在马尔凯（Marchigiana）中为 2.0%，在奇亚纳纳牛（Chianina）中为 0%。CC、HFM、IF 和 IC 变体的 AF 均低于 3%，仅在先前报道过的品种群体中检测到变体。考虑到单一品种中一个精选的雄性群体，奇亚纳纳牛（Chianina）的 PMT1、IC 和 IF 的携带者患病率分别为 11.9%、7.7%和 6.4%。罗曼纳拉牛（Romagnola）的 PCS 携带者患病率为 23.4%、PMT2 为 6.7%、HFM 为 4.1%、CC 为 3.2%、PMT1 为 2.0%。马尔凯（Marchigiana）的 PMT1 携带者患病率为 9.1%，PCS 携带者患病率为 4.0%。就罗曼纳拉牛（Romagnola）而言，该群体中总共存在五种缺陷等位基因，这阻碍了基于预防携带者进行人工授精的总体方法。然而，识别携带者可以允许有意识的交配，以防止纯合后代的风险以及杂合后代的传播。因此，建议对所有已知的七个有害等位基因进行系统基因分型，以防止携带者之间的危险交配，特别是避免受影响的后代的发生。
