Phenotypes

In a textbook example of how to make use of clinical information to identify a comparative candidate gene (based on the homologous human disorder) namely KRT5 (keratin 5), Ford et al. (2005) showed that this disorder in the offspring of a Friesian-Jersey bull is due to a 4051G>A base substitution in the bovine KRT5 gene, leading to an E478K amino-acid substitution. The bull turned out to be mosaic for a de novo mutation. Jacinto et al. (202...

In four Belgian Blue calves, Sartelet et al. (2015) identified the causal mutation as a nonsense mutation [c.7825C>T] "in the LAMA3 gene that creates a premature stop codon (p.Arg2609*) in exon 60, truncating 22% of the corresponding protein".

The double-muscle trait in cattle is characterised by an increase in muscle mass of approx 20%, resulting in substantially higher meat yield, a higher proportion of expensive cuts of meat, and lean and very tender meat, for which a substantial premium is paid. The trait is autosomal recessive, and the locus has been given the symbol mh. It occurs at such a high frequency in Piedmontese and Belgian Blue cattle that it is characteristic of these...

Comparison of whole-genome sequence by Sartelet et al. (2014), from four affecteds and eight control Belgian Blue non-carriers, revealed three SNVs "[c2244G>C + c2248T>C + c2250C>A] located in exon 23 of the CLCN7 gene encoding the anion transport protein ClC-7". The first of these is synonymous, but the second and third jointly cause "a tyrosine to glutamine substitution (TAC>CAA: Y750Q)" in a highly conserved region of the protei...

Recognising the close resemblance of this disorder in Chianina cattle to Brody disease in humans, Drögemüller et al. (2008) illustrated the power of the candidate-gene approach by showing that this disorder in Chianina cattle is due to a missense mutation in the bovine version of the "Brody gene" - ATP2A1. Interestingly, another mutation in this same gene causes a far more severe set of clinical signs: congenital muscular dystonia 1 (OMIA 0014...

Michot et al. (2016): "a one base pair insertion (Chr14: g.23995411_23995412insA) that affects the retinitis pigmentosa-1 gene (RP1) . . . [and] is predicted to cause a frameshift at codon 791 and to terminate the protein 13 amino acids later (p. R791KfsX13)".

"Affected animals have a crooked tail and shortened head, growth retardation, extreme muscularity and spastic paresia, although some characteristics show variable penetrance. CTS is not lethal per se, but causes substantial economic losses due to growth retardation and treatment." (Charlier et al., 2008)