Phenotypes

Using inferred haplotypes from the 1000-bull-genomes project, Hayes et al. (2013) announced the discovery of the likely HH3 causal mutation. Using exome capture and next-gen sequencing, McClure et al. (2014) confirmed and validated Hayes et al. (2013)'s causal mutation mutation as "a non-synonymous SNP (T/C) within exon 24 of the Structural Maintenance of Chromosomes 2 (SMC2) on Chromosome 8 at position 95,410,507 (UMD3.1). This polymorphism ...

For eight of the nine haplotypes with a significant effect on calving rate (see Mapping section), Fritz et al. (2013) searched for causal mutations via whole-genome sequence data from 25 Holstein, 11 Montbéliarde and nine Normande bulls which had made major contributions to their breed. Specifically, they filtered "for mutations that were (a) located at+or –6 Mb from the detected haplotype (b) carried in the heterozygous state by the carrier b...

Sieck et al. (2020): "Whole-genome sequencing (WGS) of 20 animals [including 3 affected calves] led to the discovery of a variant (Chr26 g. 14404993T>C) in Exon 3 of CYP26C1 associated with MD. This missense mutation (p.L188P), is located in an α helix of the protein, which the identified amino acid substitution is predicted to break"

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...