Fall 2017 Saber Tails 51
Petit Basset Griffon Vendéen Club of America
17. The function of this protein is not clear, but different mutations in this same gene lead to POAG in the Basset Hound
and Basset Fauve de Bretagne, and to primary lens luxation in many breeds. Mutations in the related ADAMTS10 lead to
POAG in the Beagle and Norwegian Elkhound. Clearly this family of proteins is important for eye health!
The Animal Health Trust developed a genetic test to detect the
POAG mutation in PBGVs mutation that required a simple cheek
swab. To motivate owners to have their PBGVs tested, the PBGV
Health & Rescue Foundation reimbursed owners for most of the
cost of the test if they made the results of their test public. As
the data accumulated, it was clear that the glaucoma problem
was worse than we thought.
The cheek swab test had the capability of showing whether a
dog is clear of disease, a carrier, or destined to be affected by
glaucoma. It is important for you to know whether your dog has
inherited bad POAG genes from both of his/her parents since, in
that case, you must have your dog’s eyes checked immediately.
The data as of July 2017 indicate that, of 401 U.S. dogs tested, 12
inherited the POAG mutation from both parents and either are
affected by glaucoma already or will be affected. That doesn’t
sound too bad, but ominously 157 of the 401 dogs are carriers
of the POAG mutation. Every time a carrier is bred to a carrier it is likely that one or more puppies will be affected.
One way to express the problem is to calculate the
number of ADAMTS17 genes in the US PBGV popula-
tion that have the POAG mutation; this is known as the
allele frequency. As an example, let’s look at the July
numbers for US dogs whose tests show they are clear,
carriers, and affected. Data from the Animal Health
Trust show that of the 401 dogs who have been tested,
there were 232 clear dogs, 157 carriers and 12 affect-
ed. Each dog has two ADAMTS17 genes, or alleles; one
from each parent.
232 clear dogs = 464 genes without the mutation
157 carriers = 157 clear genes and 157 mutant genes
12 affected dogs = 24 mutant genes
Therefore, the 401 dogs collectively have 621 clear al-
leles and 181 mutant alleles. In other words, 23% of the
ADAMTS17 genes circulating in the US PBGV popula-
tion carry the POAG mutation. That’s a lot.
The POAG test results for PBGVs around the world are
updated each month on the UK’s BGV Club website
(http://www.bgvclub.co.uk/eyes). Those data show
that the problem is even more serious in the UK, where
there are 24 affected dogs known at this time.
Given these numbers, the POAG mutation cannot be
eliminated quickly from the gene pool. It would be dev-
astating to the breed to eliminate all carriers (40% of the
Has your PBGV been tested for POAG?
It is easy to do. Go to the Animal Health Trust webpage
for canine DNA testing (http://www.ahtdnatesting.co.uk/
test-category/canine/), click on ‘P’, then on PBGV, and fi-
nally on POAG. You will be directed to the online web-
shop where you can purchase the POAG test kit for £48
(approx. $65). A cheek swab kit will be mailed to you and,
within a few weeks of submitting a swab, you will receive
an email with the test results.
Don’t stop there! Now you should submit the test re-
sults to OFA and then you will be eligible for a $40 reim-
bursement from the PBGV Health & Rescue Foundation!
Instructions can be found here: (https://www.pbgv.org/
Health/HealthRescue.shtml#POAG).
Bravo to the PBGV Health & Rescue Foundation for sup-
porting POAG testing of PBGVs!