Phenotypes

Bolcato et al. (2025): Genetic analysis identified a missense variant in WDR33 (omia.variant:1814) that was heterozygous in both analyzed cases [Belgian Blue cross calves] and in an estimated 40% of the paternal gametes of the mosaic [Belgian Blue] founder, but absent in both dams and controls. ... The genetic findings were most consistent with a likely pathogenic dominant de novo mutation in WDR33 as the underlying cause of the observed conge...

This disorder is of particular interest in cattle, because it is one of the few cases in which an embryonic lethal has been identified. (By their very nature, embryonic lethals are difficult to identify; their only manifestation is a return to service.) To date, the only known cause of this disorder in cattle is a nonsense mutation in codon 405 of the UMPS gene, resulting in a complete deficiency of functional UMPS (Schwenger et al., 1993). Si...

The first occurrence of this disorder in any domestic species was reported by Angelos et al. (1995), in Charolais cattle.

Häfliger et al. (2021) investigated “the two Braunvieh populations reared in Switzerland, the dairy Brown Swiss (BS) and the dual-purpose Original Braunvieh (OB). We performed a genome-wide analysis of array data of trios (sire, dam, and offspring) from the routine genomic selection to identify candidate regions showing missing homozygosity and phenotypic associations with five fertility, ten birth, and nine growth-related traits. In addition,...

Jacinto et al. (2022): "A trio whole-genome sequencing approach was carried out and identified a private homozygous missense variant in LAMB1 affecting a conserved residue (p.Arg668Cys)."

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. ...

Nogueira et al. (2022) "A rare SNP, predicted to be deleterious was discovered within a conserved WD40 domain repeat-encoding region ... of the bovine autosomal ... EML5 gene ... in an Angus bull ... with low fertility." The authors "demonstrate that this mutant allele is present in many breeds world-wide." 

Comparison of sequence of the 713kb candidate region (mentioned in the mapping section above) in an obligate carrier, one of its offspring, 43 members of the Fleckvieh breed (in which the disorder has never been reported) and 191 non-Fleckviehs from the 1000-bulls project revealed 2 candidate causal SNVs: a coding variant and an intronic variant of the gene UBE3B, which encodes ubiquitin protein ligase E3B, and mutations in which cause a simil...

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...