Ichthyosis Jack Russell Terrier type (TGM1-related) - Dog

What does this test examine?

This genetic test analyses the TGM1 LINE-1 insertion variant in Jack Russell Terrier. The disorder is known as Ichthyosis Jack Russell Terrier type / TGM1-deficient lamellar ichthyosis, 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?

TGM1 encodes transglutaminase 1, an enzyme needed for building the outer skin layer. A LINE-1 insertion disrupts this process and causes an abnormal, scaling skin barrier. 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.

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 TGM1-related ichthyosis.