Phenotypes

In a remarkable indication of the power of whole-genome sequence analysis, Daetwyler et al. (2014) identified a causal mutation for this disorder in Holstein Friesian cattle as a missense mutation (g.32475732G>A [UMD3.1 reference sequence]; p.Gly960Arg, omia.variant:223) in the COL2A1 gene (which encodes the alpha-1 chain of type II collagen), by comparing the sequence of only two affected calves with sequence from bulls in the 1000-bull-ge...

Bourneuf et al. (2017): a de novo likely causal variant in Charolais is single-base insertion in EDAR, resulting in a frameshift variant g.44462236_44462237insC; p.P161RfsX97

Gutiérrez-Gil et al. (2007): c.64G>A Jolly et al. (2008): c.50_52delTTC Laible et al. (2021): "To better adapt dairy cattle to rapidly warming climates, we aimed to lighten their coat color by genome editing. ... Using gRNA/Cas9-mediated editing, we introduced a three bp deletion in the pre-melanosomal protein 17 gene (PMEL) proposed as causative variant for the semi-dominant color dilution phenotype observed in Galloway and Highland cattl...

Boussaha et al. (2023): "Homozygosity mapping followed by analysis of the whole-genome sequences of two [affected Charolais] cases and 5031 control individuals enabled us to prioritize a splice donor site of ITGA6 (c.2160 + 1G > T; Chr2 g.24112740C > A) as the most compelling candidate variant. ... RT-PCR analyses revealed increased retention of introns 14 and 15 of the ITGA6 gene in a heterozygous mutant cow compared with a matched cont...

By whole-genome sequencing a single affected Charolais calf, and concentrating on comparative functional candidate genes based on careful diagnosis, Peters et al. (2015) identified the causative mutation to be "a 4.4 kb deletion involving exons 17 to 22" of the ITGB4 gene. The authors noted that "The transcript of the mutant allele lacked information regarding a significant part of the encoded protein since the deletion led to a frameshift and...

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

By comparing whole-genome sequenced data (from 2 affecteds and one control) in the candidate region (see Mapping section), and filtering resultant candidate variants, Duchesne et al. (2018) narrowed the field down to "a single substitution in exon 5 of KIF1C (chr19:27041449 C/T). For easier comprehension and since KIF1C gene in cattle is on the reverse strand, the substitution will be referred as KIF1C G>A in order to match with the transcr...

Bourneuf et al. (2017) detected SOWAHB g.93487577G>T; p.Q379K as a de novo recessive potentially lethal mutation from an analysis of whole-genome-sequence of a Charolais AI bull. No information was provided on the descendants of this bull.

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...

Genotyping of the three affected daughters with a 777,000 SNP chip, combined with whole-genome sequencing of one of the affected daughters, enabled Capitan et al. (2012) to identify the causative mutation as a 3.7Mb deletion encompassing the genes ARHGAP15, GTDC1 and ZEB2. Comparison with the homologous human disorder (see MIM entry above) implied that the syndrome is primarily due to the deletion of ZEB2. Gerhke et al. (2020) identified "an 1...

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)".

By sequencing a strong positional candidate gene, namely TWIST1, Capitan et al. (2011) identified a small duplication (c.148_157dup (p.A56RfsX87)) that inactivates the gene. This frameshift mutation segregates perfectly with type 2 scurs.