Imerslund-Gräsbeck Syndrome IGS
(Vitamin B12 Deficiency)

A DNA test for Vitamin B12 deficiency (Imerslund-Gräsbeck Syndrome – IGS) in Border Collies is available at the Animal Health Trust. Discounts are available in our combination packages.


Vitamin B12 deficiency (Imerslund-Gräsbeck Syndrome – IGS) is  condition found in Border Collies
Deficiency of vitamin B12 leads to megoblastic anaemia, neurological symptoms, mild proteinuria, failure to thrive and irreversible damage to the brain and nervous system if left untreated.

The disease can be treated by dietary supplements of the vitamin. The mutation causing this condition, has been identified as a single-base pair deletion in the Cublin (CUBN) gene by researchers in Switzerland.


How  is the disease inherited?

When two carriers are crossed, 25% (on average) of the offspring will be affected by the disease, 25% will be clear and the remaining 50% will themselves be carriers.

Border Collie owners who use the IGS DNA test will be sent results identifying their dog as belonging to one of three categories.  In all cases the terms ‘normal’ and ‘mutation’ refer to the position where this mutation occurs in Border Collies.  It is not possible to learn anything about any other region of DNA from this  test.



CLEAR: these dogs have two normal copies of DNA and will not develop IGS as a result of the IGS mutation.

CARRIER: these dogs have one copy of the mutation and one normal copy of DNA. These dogs will not develop IGS themselves as a result of the IGS mutation but they will pass the mutation on to approximately 50% of their offspring.

AFFECTED: these dogs have two copies of the IGS mutation and will be affected with IGS.

We cannot exclude the possibility that carriers might develop a similar condition due to other mutations they might carry that are not detected by this test.


For more information please contact us and we’ll be happy to deal with your enquiry.

Reference: A Frameshift Mutation in the Cubilin Gene (CUBN) in Border Collies with Imerslund-Gräsbeck Syndrome (Selective Cobalamin Malabsorption), Marta Owczarek-Lipska, Vidhya Jagannathan, Cord Drögemüller, Sabina Lutz, Barbara Glanemann, Tosso Leeb, Published:April 16. 2013 DOI: 10.1371/Journal.pone.0061144