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 a premature stop codon. It was therefore assumed that the mutant transcripts probably underwent nonsense mediated decay so that, in the final analysis, the deletion represented a loss-of-function mutation with a non-existing integrin protein in the epidermis of the affected animal." Genotyping of 162 Charolais from the same herd confirmed the association between this deletion and the disorder. Michot et al. (2015) independently mapped the disorder in Charolais and identified the same causal mutation.
