Phenotypes

The causative mutation for this disorder was discovered via the candidate gene approach. Tassi et al. (1984) reported a 10-15-fold decrease in the concentration of TG mRNA in affected cattle; Ricketts et al. (1985) reported the use of S1 nuclease assays and electron microscopy to narrow down the location of the mutation to the junction of exon 9 and intron 9; and Ricketts et al. (1987) reported the use of cloning and sequencing of genomic DNA ...

By cloning and sequencing a very likely comparative candidate gene (based on the same disorder in humans), Shuster et al. (1992; PNAS) showed that this disorder in Holstein cattle is due to a missense mutation (c.383A>G) in the CD18 gene, now known as ITGB2. This mutation was confirmed in Daetwyler et al. (2014)'s analysis of whole-genome sequence data from 234 cattle, including key ancestors of the Holstein-Friesian, Fleckvieh and Jersey b...

Some of the resistant cattle described in this entry are genetically-modified organisms (GMO)