"The gross phenotype was manifest as a disheveled pelage shortly after birth, generalized scaling, and adherent brown scale with erythema of the abdominal skin (Mauldin et al. 2015)...Affected dogs exhibited diffuse laminated to compact orthokeratotic hyperkeratosis with hypergranulosis and mild acanthosis. The epidermis had a prominent granular layer, and multifocal granular layer keratinocytes displayed a perinuclear clear space. Malassezia could be found within the corneal layer in at least one sample in approximately 60% of cases. The yeast were typically present without an inflammatory response. Ultrastructurally, the epidermis showed discontinuous lipid bilayers, unprocessed lipid within corneocytes, and abnormal lamellar bodies (Mauldin et al. 2015)...As reported by Casal et al. (2017), "Obligate carriers were confirmed to be heterozygous for this variant, and 150 clinically non-affected dogs of other breeds were homozygous for the wild-type gene. Among 800 American bulldogs tested, 34% of clinically healthy dogs were discovered to be heterozygous for the defective allele." [From OMIA]