Dilated cardiomyopathy / DCM3 (RBM20-related) - Schnauzer

What does this test analyse?

This genetic test analyses the RBM20 c.2472_2493del variant in Schnauzers. The condition is known as dilated cardiomyopathy, DCM, DCM3, RBM20-related DCM and dilated cardiopathy.

RBM20 encodes an RNA-binding protein involved in RNA processing in cardiac muscle cells. The tested 22 bp deletion causes a frameshift in RBM20. In dogs with two copies of this variant, this form of DCM is strongly linked to cardiac enlargement, reduced pumping ability and increased risk of early heart failure.

What does DCM3 mean for the dog?

Dilated cardiomyopathy affects the heart muscle. The heart, especially the left ventricle, can enlarge and contract less effectively. This can reduce circulation and lead to arrhythmias or congestive heart failure. In the described Schnauzer form, the condition can be severe at a young age.

Possible signs include exercise intolerance, fainting or collapse, shortness of breath, weight loss, fluid accumulation in the abdomen and sudden death due to arrhythmia. Because carriers do not need to develop typical recessive DCM3, the variant can remain hidden in breeding lines.

Practical value of this test

This test is especially valuable for breeders who want to actively prevent DCM3 in Schnauzer lines and for veterinarians or owners looking for a genetic explanation in compatible heart disease.

• The result distinguishes clear dogs, carriers and dogs with two copies of the tested RBM20 deletion.
• Breeders can avoid carrier x carrier matings and directly reduce the risk of puppies with this serious RBM20-related form of DCM.
• Valuable carriers can remain in the population responsibly when combined only with clear partners.
• In young Schnauzers with arrhythmia, exercise problems or signs of heart failure, the DNA result provides a concrete genetic direction for follow-up.
• The test helps breeders communicate more clearly about DCM3 status, risk management and planned matings within their lines.

Inheritance and interpretation

DCM3 due to this RBM20 variant follows autosomal recessive inheritance. N/N means the tested deletion was not detected. N/del means carrier: the dog carries one copy and can pass the variant on. del/del means the dog carries two copies; this genotype causes the tested RBM20-related DCM3 form and calls for targeted breeding and health follow-up.