Congenital hypomyelinating polyneuropathy / HPN (MPZ, MTMR2 and SH3TC2) - Golden Retriever

What does this test detect?

This genetic panel test analyses three variants for congenital hypomyelinating polyneuropathy in Golden Retrievers: MPZ c.434T>C, MTMR2 c.1479+1G>A and SH3TC2 c.1924C>T.

Other names for this condition

The condition is also described as congenital hypomyelinating polyneuropathy, HPN, hypomyelinating polyneuropathy, peripheral hypomyelination and a canine Charcot-Marie-Tooth-like neuropathy.

What does this mean for the dog?

HPN primarily affects the peripheral nervous system. Reduced formation of myelin, the insulating layer around nerve fibers, makes nerve signals slower and less efficient. Affected puppies may show early muscle weakness, easy fatigue, ataxia, tremors, low muscle tone, delayed motor development, swallowing difficulties, megaesophagus, vomiting or breathing problems. The three variants can cause similar signs, but differ in gene and inheritance.

Inheritance and result

The MPZ variant acts as autosomal dominant: one copy can cause HPN. The MTMR2 and SH3TC2 variants act as autosomal recessive: one copy means carrier status, while two copies cause HPN. This makes a three-subanalysis panel more useful than a single variant when assessing HPN risk in Golden Retrievers.

Practical value of this test

• Breeders receive clarity on three known HPN variants within the breed in one test.
• The result helps identify both dominant MPZ risk and recessive carriers of MTMR2 and SH3TC2.
• For breeding plans, the test makes it possible to avoid risk matings while preserving healthy lines deliberately.
• In young dogs with neuromuscular signs, the test can help explain an inherited peripheral nerve disorder genetically and guide screening of relatives.