Phenotypes

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.

Jacinto et al (2025) investigated two half-sib Angus calves with chondrodysplasia leading to primordial disproportionate dwarfism in a whole genome sequencing approach: "Assuming a dominant MOI [mode of inheritance], a heterozygous pathogenic missense variant was found in exon 6 of PRDM10 leading to an amino acid exchange in PRDM10 at position 289, located in the PR-SET domain (Chr29:g.36138136G > A; c.866C > T; p.Pro289Leu) [omia.varian...

Bourneuf et al. (2017): a de novo likely causal variant is COL1A1 p.1049_1050delinsS in Fleckvieh Petersen et al. (2019): "Whole-genome sequencing revealed the presence of a missense mutation in the alpha 1 chain of collagen Type I (COL1A1), for which both calves were heterozygous. The variant resulted in the substitution of a glycine residue with serine in the triple helical domain of the protein; in this region, glycine normally occupies eve...