1st June 2018
The Roslin Institute have published their research into severe goniodysgenesis and glaucoma in the Border Collie
https://www.biorxiv.org/content/biorxiv/early/2018/05/14/321406.full.pdf
Animal Genetics have now launched a DNA test for the detection of Goniodysgenesis and Glaucoma Susceptibility in the Border Collie
DETAILS:
Goniodysgenesis and Glaucoma Susceptibility -Border Collie
DESCRIPTION:
Goniodysgenesis is a condition cause by the abnormal and incomplete development of the anterior chamber which can result in excessive pressure buildup in the eye. If the condition remains untreated, increased pressure in the eye will eventually result in permanent damage to the optic nerve and blindness.
Most forms of glaucoma can be placed into two categories, primary and secondary. The term primary glaucoma is used to describe those types of glaucoma caused by an inherited physical or physiological trait that an animal has been predisposed to based on genetics. These traits are generally recessive and passed down from one generation to the next.
Secondary glaucoma is a term referred to when the disease is triggered by something other than genetics. Trauma in the eye can cause bleeding, swelling, and inflammation to occur. As the eye heals, scar tissue may form, impacting the normal drainage of fluid resulting in increased pressure in the eye.
More than 40 dog breeds are genetically predisposed to goniodysgenesis including the Flatcoated Retriever, Welsh Springer Spaniel, Cocker Spaniel, American Cocker Spaniel, English Springer Spaniel, Basset Hound, Border Collie, Golden Retriever, Leonberger and Dandie Dinmont Terrier. Unfortunately, a large percentage of dogs affected by glaucoma will become blind in the affected eye within the first year, regardless of medical or surgical treatment.
Symptoms associated with primary glaucoma include: Severe pain, sensitivity to light, winking spasms, eye appears to have fallen into the socket, raised third eyebrow, dog winces when you touch his or her head, watery eyes, behavioral change (hiding, refusal to eat), red eye, and dilated pupils.
The discovery of a genetic variant on the OLFML3 gene was performed at The Roslin Institute, University of Edinburgh and the Mater Research Institute-UQ, Brisbane Australia. The individuals credited for this work are Kim M Summers, Ailsa J Carlisle, Carys A Pugh and Lindsay L Farrell. Based on this discovery, Animal Genetics develop an assay to detect the genetic variant associated with Border Collie Glaucoma. A paper will be published outlining all of the work.
SAMPLE TYPE:
Animal Genetics accepts buccal swab, blood, and dewclaw samples for testing. Sample collection kits are available and can be ordered at Canine Test Now.
RESULTS:
Animal Genetics offers DNA testing for Glaucoma susceptibility in Border Collies. The genetic test verifies the presence of the recessive mutation and presents results as one of the following:
G/G - Affected:
The dog carries two copies of the mutant gene and is homozygous for the OLFML3 mutation associated with BCG. The dog is very susceptible to developing glaucoma and will always pass a copy of the mutation to its offspring.
N/G - Carrier:
One copy of the OLFML3 mutation associated with BCG. Dog is a carrier and can pass on a copy of the defective gene to its offspring 50% 0f the time.
N/N - Clear:
Sample tested negative for the OLFML3 mutation associated with BCG, and will not pass on the defective gene to its offspring.
The PBHF are delighted to announce that after many years of research the Pre-Disposition to Glaucoma DNA test is now commercially available via Animal Genetics. The discounted cost via a PBHF clinic is £30. The recommendations are to not breed from affected stock and for carriers to only be mated to clears. Due to the number of carriers found it is not recommended that all carriers are removed from breeding programs as this may decimate genetic diversity within the breed. The test was officially launched at Scottish and Wessex Border Collie Club open shows on 19th and 20th May and is also available via post by contacting pbhfsecretary@outlook.com
The option for sending results to this database has also been added to our submission form, and will be added to the existing database as a new column in the sheets!
22nd January 2018
From January 2018, all new tests will be listed on each page BLUE to show the official grading system being incoporated in the UK as below:
- Affected= A dog listed on this site as "Affected" means that the dog has undergone a gonioscopy test by a recognised opthalmic specialist and has some abnormality to exclude the dog from being given a "normal or unaffected" physical status for it's eyes. In the U.K. as of July 2017 the B.V.A. had commenced a pilot scheme which will be reviewed in November 2017 by the BVA.
A dog that is listed as "Affected" does not necessarily mean that the dog has, or will develop Glaucoma. At present, there is no worldwide standardisation of wording given on eye examination sheets so the usage of the words "affected" or "unaffected" are those adopted in the UK. In other countries, words as "clear" or "normal" may be preferred. To save confusion over the phenotype or genotype of any given dog, the word "clear" is not used in these databases. Should a DNA test become available to clarify a dog's genotype, the word clear will be used in that context.
It should be remembered that at present we only have the possibility of defining whether a dog is normal or not by a physical eye examination and this in no way declares the genetic status of dog, or it's chance of passing on the condition to it's offspring. - GradesIn the U.K. from July 2017
Normal Grade 0 Highly unlikely to develop primary glaucoma
- Unaffected= Simply means that the dog has passed a physical eye test with no obvious abnormalities. It does not necessarily mean that the dog is genetically clear.
- Affected Grade 1 (in U.K.) Mildly affected – unlikely to develop primary glaucoma.
- Affected Grade 2 (in U.K.) Moderately affected – low risk of developing primary glaucoma
- Affected Grade 3 (in U.K.) Severely affected – highest risk of developing glaucoma
- Gonioscopy testing. There is a detailed pamphlet on this and other eye diseases on the British Veterinary Association website, which can be downloaded from the link below. The BVA recommends that a gonioscopy test is best performed from 6 months at the earliest, depending on eye development. Some vets will test at 3 months, but any younger is not normally advised. BVA pamplet link
Clinically unaffected cannot be an accurate description unless the gonioscopic findings are entirely normal.
The U.K. Kennel Club will continue to record under the old scheme – and the result grades will be collated , recorded and collated by the BVA.
Further information can be found on the P.B.H.F. website
22nd March 2014
Pastoral Breed Health Foundation – What’s been happening?
·Gonioscopy Project – In the U.K. we have been awaiting the figures from the BVA since the Border Collie was put onto schedule B (under investigation) . The following is the reported figures so far and comments from Ian Mason, Chief Panellist for Eye Testing in the U.K.
In the last 12 months 91 Border Collies were reported to have undergone a gonioscopy. One of these showed a severe level of goniodysgenesis and four showed lesser degrees of change. This was a slightly lower percentage of abnormality than noted in the previous years where abnormality was noted in approximately 7% of dogs examined. The percentage of goniodysgenesis seen in breeds where inherited or suspected inherited glaucoma does not occur is much less than this, probably by an order of 10 fold (i.e. a level of 0.5% goniodysgenesis or less).
Tonometry or Intra-ocular pressure measurement can tell you if an animal currently has an abnormal Intra-ocular pressure which if raised is glaucoma, but cannot tell us anything in regard to the presence or absence of goniodysgenesis. It is helpful to diagnose the presence of glaucoma but not the existence of the predisposing problem of goniodysgenesis, which we believe to be the cause of glaucoma in the Border Collie. It is important to realise that the abnormality of goniodysgenesis does not mean glaucoma will occur in all dogs where goniodysgenesis is found. It is an indicator of the pre-disposition to glaucoma development. I trust this of some help to you. Certainly the results indicate that there is a significant level of goniodysgenesis in the Border Collie breed but more examinations need to be carried out before we have knowledge as to the true incidence in this breed.
Taking the numbers from the above, it is clear how important the database is and the need for everyone to include their results – with some simple maths it is clear that we have had cases that have undergone gonioscopy and shown levels of abnormality (failures) that have not been recorded and therefore, as breeders, we are unaware who these dogs are. ·
News on the research – an application has gone in via Roslin Institute for funding on the project and we await the outcome. This would be a great break through in terms of funds to move the research on. · We also have a new researcher appointed to assist on the project and we now have an updated list of dogs where they require additional DNA samples as some of the samples have not provided enough DNA and in some cases not previously requested.
The main issue has been the poor standard of the samples returned to the PBHF from Australia following the death of our researcher Alan Wilton. We have therefore had to request more swabs and/or blood and thank people for their co-operation. ·
A review of the “control group” those not affected has also produce a new “working” list which is now being used. This will result in a closer relationship with those in the breed to help assist the hard job of locating the genes from the DNA. ·
We need everyone to use the database and send in their results and we need swabs sent in of any that are affected to help the research. Many UK breeders are using the database and assisting and it would be great to have some more entries from overseas and also DNA from the appropriate dogs. If in doubt and you think you can help please contact us.
In order to encourage owners to test and also provide information for the research – the PBHF will assist clubs putting on eye testing sessions where they are offering a discount for the goniocopy test – for example if a club offer to reduce the price by £5 then the PBHF will match it with another £5 reduction – one dog one owner. We might be able to extend this, so please look out for details or contact one of us. Good news we have extended and are offering £5 reduction at any club show or session authorised by the PBHF. For contact details please go to the PBHF website
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As of March 2014, The Animal Health Trust in the UK is looking at the genetics of goniodysgenesis and glaucoma in a number of breeds including the Border Collie. We are looking for cheek swab samples from dogs diagnosed for either/both conditions as well as those certified to be clear at the age of 5 or above (by an ophthalmologist). For further information please contact me at James.Oliver@aht.org.uk