Hypophosphatasia / HPP (ALPL-related) - Karelian Bear Dog

What does this test assess?

This genetic test analyses the ALPL c.1301T>G variant in the Karelian Bear Dog. The condition is called hypophosphatasia, HPP and ALPL-related skeletal mineralisation disorder. ALPL encodes tissue-nonspecific alkaline phosphatase, an enzyme important for normal bone and tooth mineralisation.

What does this condition mean?

In hypophosphatasia, bones and other skeletal structures are insufficiently mineralised. Affected puppies can show growth retardation, movement difficulty, muscle weakness, crouched posture, abnormal bones or joints, seizures and severely reduced viability. The result is therefore highly relevant in Karelian Bear Dog breeding lines.

Inheritance and result

The trait is inherited as an autosomal recessive condition. Dogs with two copies of the tested variant develop ALPL-related hypophosphatasia. Carriers have one copy, are usually healthy themselves, but can pass the variant to offspring.

• Clear: the tested variant was not detected.
• Carrier: one copy of the variant was detected; important for breeding selection.
• Affected: two copies were detected; this genotype causes hypophosphatasia for this variant.

Practical value of this test

This test is useful because carriers can look healthy while a mating between two carriers can produce severely affected puppies. Testing breeding dogs allows breeders to avoid risk matings, use carriers responsibly with clear partners and actively reduce HPP in the population.

• Helps identify carriers before breeding.
• Reduces the risk of puppies with severe skeletal and mineralisation problems.
• Makes breeding advice concrete in a breed with a known ALPL variant.
• Gives clear genetic explanation to buyers and veterinarians.