FanconiFAQ

Fanconi syndrome is a disorder in which the kidneys do not properly reabsorb nutrients and
electrolytes back into the body. Untreated, fanconi syndrome is usually fatal. In 1990, Dr.
Steve Gonto developed a treatment protocol for fanconi syndrome. While this protocol is
not a cure, many dogs do very well on the protocol and go on to lead relatively normal lives.
Unfortunately, even with the protocol, some dogs do not do well. My Tia, Echelon Destined
to Dance, was one of these dogs. She was diagnosed with fanconi syndrome in February
2005. Despite initially doing well on the Gonto Protocol, she died due to complications of
fanconi in August 2007 at 6 years of age.

For many years, the exact inheritance of fanconi was unknown. And, since symptoms usually
don't appear until a dog is between 4 and 8 years old, it was difficult to determine exactly
where fanconi would rear it's ugly head.

Fortunately, in July of 2007, Dr. Gary Johnson from the University of Missouri -- Columbia,
developed a linkage marker test for fanconi. With this test, it is now possible to determine if a
dog is a PROBABLE CLEAR, PROBABLE CARRIER or PROBABLE AFFECTED. More
information about the test can be found at the Basenji Health Endowment website.

Although there is quite of bit of information on the web about fanconi syndrome in basenjis,
some puppy mill and back-yard breeders are spreading blatantly FALSE information to suit
their own purposes. PLEASE read the Fanconi FAQ's below. Be an informed puppy buyer.
Do not let someone else's ignorance be the basis for your heartbreak.

Frequently Asked Questions About Fanconi Syndrome in Basenjis

I've heard there is no test for fanconi syndrome. Is this true?

Not any more! A linkage test became available in July 2007. More information about the
linkage test can be found here -- http://www.basenjihealth.org/linkage-faq.html

The breeder says that none of the parents or grandparents of the litter has fanconi
so they don't need to test, right?

Sorry, this is absolutely FALSE!! Fanconi has been determined to be a recessively inherited
trait. This means that dogs can carry one gene for fanconi (PROBABLE CARRIER) and not
have any symptoms. While a PROBABLE CARRIER will not develop fanconi, they are able to
pass the gene on to their puppies. If two PROBABLE CARRIERS are bred, they can produce
puppies with fanconi. This is what happened with my Tia. Both of her parents are still happy
and healthy at the ages of 11 and 8. You cannot tell if a dog carries fanconi just by looking at
it. To make sure your puppy won't have fanconi, at least one parent needs to be PROBABLE
CLEAR by DNA test.

I thought Fanconi was a liver disease. Can it be caused by eating the wrong food?

Fanconi is a disease of the kidneys, NOT the liver. If someone tells you otherwise they are
either uneducated or a liar or both. Google fanconi syndrome in basenjis -- Read the
information out there. Fanconi cannot be caused by eating raw food, etc. In some very rare
instances a dog could develop fanconi syndrome in response to an environmental toxin but
these cases generally reverse and generally are found in OTHER breeds. I'm on a list with
other owners of fanconi affected dogs. I've seen a couple cases of dogs from a different breed
getting environmentally induced fanconi syndrome that later resolved on it's own. ALL of the
basenjis have inherited the disease -- and this form of the disease DOES NOT GO AWAY.

The breeder said they chose not to have their fanconi test results published on the
website.

Sorry. That's not an option for them to choose! All DNA fanconi linkage test results are listed
on the OFA website. The owner does not get to choose whether or not these results are
made public. You should be able to search for the name of the dog they had tested and it
should show up. It usually takes 2-3 weeks after the test for the dog to be listed in the
database. If the breeder is telling you they chose not to put the results in OFA then they are
lying to you!

The breeder said they had their Fanconi test done at their vet, and he said their
dog is fine.

The linkage test for fanconi requires a blood draw. While their vet is likely the one who drew
the blood, their vet can NOT determine whether or not the dog carries the gene for fanconi.
The ONLY lab doing the testing for fanconi is Dr. Johnson's lab at the University of Missouri --
Columbia.

The breeder said they check the dog's urine every month for fanconi and he is
clear. Is this the same test?

NO! What they are doing is called "strip testing" or "urine glucose screening." One of the first
physical signs that a dog has fanconi syndrome is the spilling of sugar (glucose) in their urine.
Before the DNA linkage test became available, this was the best way to check dogs to see if
they were affected. This test is only effective to say that a dog is (or isn't) symptomatic. A
strip test does not prove ANYTHING other than the fact that the dog is not spilling sugar
TODAY! A dog could genetically be affected, but still strip test clear. I'll use my Tia as an
example. I started checking her urine at age 2. For the next 2.5 years, she was clear. Then I
noticed that some days she had a slight color change on the strip test. This was my first
indication that not all was well. As the fanconi progressed, the strip test would always indicate
the prescence of glucose in her urine. The only way to know the real fanconi status of a dog
is through the linkage test.

The breeder said their dog tested PROBABLE AFFECTED, but isn't showing any
symptoms. The test must be wrong, right?

Probably not. Some dogs don't become symptomatic until they are older (age 4 - 8). Some
dogs become symptomatic at a very old age (10+). And a VERY few may show no signs
whatsoever. HOWEVER -- even if the dog is showing no outward symptoms of fanconi, if it
has tested PROBABLE AFFECTED then 99 times out of 100 it DOES have fanconi, and will pass
that gene on to it's offspring.

So a PROBABLE AFFECTED should never be bred right?

Well, this is a grey area for breeders. It is generally recommended that PROBABLE AFFECTED
dogs NOT be bred. If they are bred, they MUST be bred to a dog testing PROBABLE CLEAR
to prevent any puppies from developing fanconi. In this case, all puppies will be PROBABLE
CARRIERS, but will not develop fanconi.

So what breedings can be done?

Fanconi is a recessively inherited condition. This means that for a puppy to develop Fanconi,
it has to get a gene for Fanconi from BOTH parents.

To illustrate this, let's assume that this is the normal (NO fanconi) gene:

And this is the gene for Fanconi:

So, a PROBABLE CLEAR dog has these genes:

also written:

A PROBABLE CARRIER dog has these genes:

also written:

A PROBABLE AFFECTED dog has these genes:

also written:

When the parents are bred, each puppy gets one of these genes from each parent.
So, here's what happens if you breed two PROBABLY CLEAR dogs:

The squares with one F represent a single gene from the parent (sire on top, dam on the left
side). The squares with two FF represent the genotype (or what genes) the puppies have. In
this case, ALL of the puppies would be PROBABLY CLEAR.

How about breeding a PROBABLY CLEAR to a PROBABLY CARRIER?

In this case you get:

NONE of these puppies will develop fanconi.

How about breeding a PROBABLY CLEAR to a PROBABLY AFFECTED?

In this case you get:

NONE of these puppies will develop fanconi.

Many problems arise when breeders unknowingly breed two PROBABLY CARRIERS together.

With this cross, you would expect to get the following:

Now suppose you bred a dog who is a PROBABLY CARRIER to a dog that is PROBABLY
AFFECTED.

You would expect the following:

And in the unfortunate instance where two PROBABLY AFFECTED dogs are bred to one
another:

ALL of the puppies wil be PROBABLY AFFECTED.

The bottom line is this -- Ask for proof that fanconi testing has been done! That proof will
come in the form of a certificate from OFA listing the dog as PROBABLE CLEAR (carries no
genes for Fanconi), PROBABLE CARRIER (carries one gene for Fanconi) or PROBABLE
AFFECTED (carries two genes for Fanconi). If the parents do NOT have a fanconi test OR if
at least one of them is not a PROBABLE CLEAR -- do NOT buy that puppy unless the puppy
has been tested.