Ichthyosis / ARCI (NIPAL4-related) - American Bulldog type

What does this test examine?

This genetic test analyses the NIPAL4 c.744delC variant in American Bulldog and American Bully. The disorder is known as Ichthyosis / ARCI American Bulldog type, ichthyosis, congenital ichthyosis and an inherited cornification disorder. The name ichthyosis refers to dry, scaly skin that can resemble fish scales.

What does it mean for the dog?

NIPAL4 encodes ichthyin, a protein important for lipid organisation and the skin barrier. The c.744delC deletion creates a shortened, non-functional protein. A disrupted skin barrier can lead to scaling, dry or thickened skin, a dull coat, redness, itching, fissures or secondary skin infections. Severity differs between types and breeds: some forms are mainly chronic and inconvenient, while others cause serious skin disease in young puppies. In American Bulldogs, signs can be visible soon after birth with generalized scaling, adherent brown scale and redness, especially on the abdomen.

Practical value of this test

• Breeders can identify carriers or dogs with a risk genotype before matings are planned.
• The result helps avoid matings that may produce puppies with two copies of a recessive ichthyosis variant, or helps keep dominant variants out of a breeding line.
• In young dogs with scaling, the test quickly clarifies whether the tested inherited form explains the skin problems.
• For owners, the result gives practical context for skin care, follow-up and breeding decisions.

The condition is inherited as an autosomal recessive trait. One copy makes a dog a carrier; two copies cause NIPAL4-related ichthyosis.