Phenotypes

Vaiman et al. (2022): "The genome of two affected animals was sequenced ... . ... two fully linked mutations in exon 24 of the MYH3 (myosin heavy chain) gene were detected: a 1-bp non-synonymous substitution (BTA19:g.29609623A>G) and a 11-bp frameshift deletion (BTA19:g.29609605-29609615del). These two mutations were specific to the Limousine breed, with an estimated allele frequency of 2.4% and are predicted to be deleterious. ... mRNA and...

In a reversal of the normal sequence of discovery, Li et al. (2016) discovered this phenotype AFTER identifying the causal mutation, by noticing that all Belgian Blue cattle with a particular mutation (MLPH: c.87_96del; p.Glu32Aspfs*1), which inactivates MLPH, have an expected dilution phenotype which the authors called "cool gray".

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...

Using targeted DNA capture and massively parallel resequencing of the 1.2 Mb region that contained 24 genes, Testoni et al. (2012) identified a causal mutation as a "KDM2B missense mutation (c.2503G>A) leading to an amino acid exchange (p.D835N) in an evolutionary strongly conserved domain". As the same authors report, "The KDM2B gene (also known as JHDM1B and FBXL10) encodes a histone H3 lysine 36 dimethyl (H3K36me2)-specific demethylase ....

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...

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)".

Cloning and sequencing of the bovine gene encoding molybdopterin cofactor sulfurase (MCSU, now called MOCOS) in normal and affected cattle, by Watanabe et al. (2000), revealed the causal mutation to be a 3bp deletion (c.769_771delTAC) of codon 257 (deleting Tyr) in the MOCOS gene (omia.variant:446). Murgiano et al. (2016) discovered a different mutation in the MUCOS gene as the likely cause in Tyrolean Grey cattle: "1 bp deletion in the molybd...