Phenotypes

Agerholm et al. (2016): "a single base deletion in the first exon of CHRNB1 (c.55delG) introducing a premature stop codon (p.Ala19Profs47*) in the second exon, truncating 96 % of the protein."

Häfliger et al. (2022): "Whole-genome sequencing of the parent-offspring trio revealed a de novo mutation of ADAMTSL4 in this case. The heterozygous p.Arg776His missense variant affects a conserved residue of the ADAMTSL4 gene that encodes a secreted glycoprotein expressed in the lens throughout embryonic development." The authors were careful to note that "Given that this is a single case investigation and that we have no functional confirmat...

By cloning and sequencing a very likely comparative candidate gene (based on the homologous human disorder), Kunieda et al. (1999) identified a missense mutation (A to G) in the bovine LYST gene, producing an amino-acid substitution of histidine to arginine (H2015R) in the resultant peptide.

Also known as Ellis-van Creveld Syndrome

Whole-genome sequencing of an affected calf and both its parents, followed by filtering of variants, enabled Häfliger et al. (2020) to identify a stop-lost mutation in FGFR3 as the likely causal variant, namely g.116,767,863C>A; NM_174318.3: c.2408G>T; [XM_024992994.1: p.(Ter803Leuext*93), which is "predicted to extend the sequence at the C‐terminal end with 93 additional amino acids". This variant resulted from a de novo mutation in the...

To date, all cases of this lethal disorder in cattle appear to be due to the same mutation, namely a nonsense mutation in the 5th of 9 exons of the ASS gene. Normal bovine ASS is a peptide containing 412 amino acids; the mutation occurs in the 86th codon.

Armed with the knowledge that TYRP1 in Dexter cattle is a strong positional candidate gene for the dun phenotype (see Mapping section above), Berryere et al. (2003) showed that dun brown coat colour in Dexter cattle is due to homozygosity for a H434Y amino acid substitution in TYRP1, due to "a C to T change in nucleotide 1300 within exon 7" of the TYRP1 gene. [FN 10 Sep 2005; 21 Sep 2012]. See also OMIA:001821-9913 : Coat colour, albinism, ocu...

For information relating to Bos indicus cattle see: OMIA 001199-9915 : Coat colour, extension in Bos indicus

By cloning and sequencing a very likely comparative positional candidate gene (see the Genetic mapping section above), Seitz et al. (1999) reported that a missense mutation at 654 bp (amino acid 193, Ala>Asp) in the mast cell growth factor (MGF) locus is responsible for the roan phenotype in Belgian Blue and Shorthorn cattle (Mohammad Shariflou. The MGF gene is now called KITLG (10/11/2006; FN 15/9/2012)

By cloning and sequencing a very likely comparative candidate gene (based on the homologous human disorder), Dennis et al. (2000) identified two causal mutations in Brahman cattle, namely a frameshifting 2-bp deletion (c.1057delTA; the "E7" mutation) and a nonsense mutation (c.1783C>T; p.Arg595Ter; the "E13" mutation) in the bovine GAA gene; and a 2-bp frameshifting deletion (c.2454delCA; the "E18" mutation) in Shorthorns.

By sequencing the most likely functional positional candidate gene from the mapped region (see Mapping section), Littlejohn et al. (2014) identified a causal mutation as a "nonsynonymous SNP in exon 5 [that] encodes a p.Cys221Gly substitution highly conserved across vertebrates and other structurally related hormones, disrupting one of three disulphide bonds defining the three-dimensional (3D) structure of mature prolactin hormone" (ss10672894...

As reported by Schwarzenbacher et al. (2016),"Homozygous calves suffer from chronic airway disease resulting in poor growth performance and high juvenile mortality. The respiratory manifestations resemble key features of diseases resulting from impaired function of airway cilia." As pointed out carefully by Schwarzenbacher et al. (2016), not all homozygotes die, i.e. the lethal allele has incomplete penetrance.

By cloning and sequencing a very likely comparative candidate gene (based on the homologous disorder in humans and mice), Pierce et al. (2001) identified a causal mutation as a "a cytidine to adenine transversion at position 156 of the Glra1 gene (156C>A). The 156A allele is predicted to substitute a termination codon for a tyrosine codon (Y24*) in exon 2 . . . This substitution is predicted to result in a prematurely truncated protein that...

In the words of Charlier et al. (2008): "a missense mutation in exon 39 (A5804G) resulting in an H1935R substitution in the fourth extracellular loop". The His (normal) form of the peptide is conserved in all vertebrates sequenced to date. (FN 080330) Whole-genome sequencing of the affected Shorthorn calf described by O'Rourke et al. (2017), and subsequent checking for deleterious variants in functional candidate genes, enabled Woolley et al. ...

Shan et al. (2020) reported "a Holstein sire named Tarantino who had been approved for artificial insemination that is based on normal semen characteristics (i.e., morphology, thermoresistance, motility, sperm concentration), but had no progeny after 412 first inseminations".