Genetic characterisation of the ITGB4 mutation. Whole genome sequencing of the affected calf (shown above) revealed the presence of a homozygous 4809 bp sized deletion on cattle chromosome 19 (shown in red). The deleted segment contains the coding exons 17 to 22 of the ITGB4 gene (shown in blue). Note that, taking into account the gap in the reference sequence, the actual size of the deletion is 4405 bp. A diagnostic PCR performed on genomic DNA using a combination of three allele-specific primers allows genotype differentiation (shown below). The gel picture shows the affected calf (del/del), its heterozygous dam (del/wt) and a normal control (wt/wt).