Vitamin D-resistant rickets / HVDRR type II (VDR-related) - Pomeranian

What does this test analyse?

This DNA test analyses the VDR c.462delG variant in the Pomeranian. The condition is known as vitamin D-resistant rickets, HVDRR, VDDR type II, VDDR-2A and hypocalcaemic rickets.

What does this condition mean?

The VDR gene encodes the vitamin D receptor. This receptor is needed to translate active vitamin D signalling into normal calcium and phosphate regulation. With this variant, the body responds poorly to active vitamin D, so young dogs can develop problems with bone mineralisation, calcium balance and growth.

Affected dogs can develop weakened or deformed limbs, lameness, poor growth, low calcium levels and hair loss on the head, chest or limbs. Because this is an inherited receptor disorder, the signs can appear despite normal care or feeding.

Inheritance and result

This trait is inherited as an autosomal recessive condition. A dog with N/N does not carry the tested deletion. A dog with N/delG is a carrier. A dog with delG/delG is genetically affected and develops the tested VDR-related form of vitamin D-resistant rickets.

Practical value of this test

This test gives breeders and owners clarity about a serious inherited bone and calcium-metabolism disorder that remains hidden in carriers. The result supports targeted breeding selection and helps avoid risk matings in time.

• Reliably distinguishes clear, carrier and genetically affected dogs.
• Helps prevent carrier-to-carrier matings and reduces the risk of affected puppies.
• Adds confidence when selecting breeding dogs in lines where the variant may be relevant.
• Supports early recognition and focused follow-up when a puppy has a genetic risk genotype.
• Makes communication with puppy buyers clearer because the hereditary status of breeding dogs is documented.

Result in brief

• N/N: the tested VDR deletion was not detected.
• N/delG: the dog is a carrier and can pass on the variant.
• delG/delG: this genotype causes the tested VDR-related HVDRR type II.