Copper toxicosis modifier / RETN (RETN-related) - Labrador Retriever

What does this test assess?

This genetic test analyses the RETN c.19C>T variant in Labrador Retriever. The disorder and risk profile are described as copper toxicosis, copper storage disease, copper accumulation, copper-associated hepatopathy and copper-associated chronic hepatitis. This test analyses a RETN variant used as a copper toxicosis modifier in Labrador Retrievers. The variant has been linked to lower hepatic copper values in research, but is most useful when interpreted together with ATP7A and ATP7B.

What does this condition mean?

Copper is required for normal metabolism, but excess copper in the liver damages liver cells. Dogs with copper toxicosis can appear normal for a long time and later develop increased liver enzymes, poor appetite, vomiting, lethargy, weight loss, jaundice, behavioural change, chronic hepatitis or liver cirrhosis. Diet, other genetic factors and breed background all influence how strongly the genotype is expressed.

Inheritance and result

RETN does not follow a classic Mendelian disease inheritance pattern here. The test is used as modifier information: one or two copies can influence the copper profile, especially together with ATP7B and ATP7A.

• Clear: the tested variant was not detected.
• Carrier/modifier: one copy of the variant was detected and is relevant for breeding or risk assessment.
• Two copies/highest variant dose: the variant is present twice, or for X-linked ATP7A present on the single X chromosome of a male.

Practical value of this test

This DNA test is practically useful because copper accumulation often becomes visible only late. An early genetic result helps breeders avoid risk matings, helps owners understand which dogs deserve extra attention and supports more targeted follow-up when liver values or family history make that relevant.

• Helps plan matings and identify dogs with relevant risk information.
• Enables combined interpretation with other copper metabolism tests.
• Provides concrete information for breed-focused selection and liver-health follow-up.