Severe skin flaking, “disheveled look”, scaly looking skin. The gross phenotype was recognizable within 1 to 2 weeks of birth as a disheveled pelage with generalized soft, white scale. The glabrous skin of the abdomen was discolored light brown and mildly erythematous with diffusely adherent light brown scale. The clinical signs either did not change into adulthood or worsened slightly and often complicated by Malassezia overgrowth. Pruritus was variable and appeared to correlate with Malassezia overgrowth.
Dogs are often euthanized due to extremely high maintenance therapy.
Autosomal recessive
Severe and diffuse laminar orthokeratotic hyperkeratosis with mild acanthosis.
NIPAL4 and XM_005619252.2:c.744delC
Explanation of Results
Genotype |
Phenotype |
Interpretation |
2-2 (Homozygous Disease Variant) |
Unhealthy (Affected) |
Homozygous Affecteds (2-2) are expected to develop signs consistent with Ichthyosis and all of their offspring will inherit a disease variant allele. Parents, offspring and relatives should also be tested. You may choose to contact us for a consultation on the management of this disease. 1 = Normal allele; 2 = Variant allele. |
1-2 (Heterozygous) |
Healthy (Carrier) |
Heterozygous Carriers (1-2) are not expected to develop signs of Ichthyosis but each of their offspring has a chance of inheriting a disease variant allele. Parents, offspring and relatives should also be tested. 1 = Normal allele; 2 = Variant allele. |
1-1 (Homozygous Normal) |
Healthy (Normal, Clear) |
Homozygous Normals (1-1) are not expected to develop signs of Ichthyosis and none of their offspring will inherit the disease variant allele. 1 = Normal allele; 2 = Variant allele. |
Casal ML, Wang P, Mauldin EA, Lin G, Henthorn PS. A Defect in NIPAL4 Is Associated with Autosomal Recessive Congenital Ichthyosis in American Bulldogs. PLoS One. 2017 Jan 25;12(1):e0170708. doi: 10.1371/journal.pone.0170708. PMID: 28122049; PMCID: PMC5266318.
Mauldin EA, Wang P, Evans E, Cantner CA, Ferracone JD, Credille KM, Casal ML. Autosomal Recessive Congenital Ichthyosis in American Bulldogs Is Associated With NIPAL4 (ICHTHYIN) Deficiency. Vet Pathol. 2015 Jul;52(4):654-62. doi: 10.1177/0300985814551425. Epub 2014 Oct 16. PMID: 25322746; PMCID: PMC4492690.