|
|
|
|
|
Late in 2006 a new DNA test for FN (Familial Nephropathy) was developed by Dr. Lee's and his team at the A & M University in America, became available to locate the gene mutation for this disease. This is a major breakthrough for the health of the Cocker Spaniel.
Dr. Lees has stressed that " with WISE use of the test, using carriers on clears is OK " (quote). He emphasised how the test will enable us to rid our lines of the possibility of producing affected animals in just one generation, and how it is important not to lose quality within the gene pool whilst eradicating the disease. As in any hereditary disease, an animal who is a carrier is physically normal, and will not be at risk of producing the condition in the future if breeding is controlled (by only mating to a clear animal). Use of the test gives us the opportunity to prevent death from FN.
FN is inherited as a recessive trait. This means a disease gene must be inherited from each parent in order to cause disease in an offspring. A carrier has one disease gene and one normal gene, and is termed “heterozygous” for the disease. A normal dog has no disease gene and is termed “homozygous normal” – both copies of the gene are the same. And a dog with two disease genes is termed “homozygous affected” – both copies of the gene are abnormal.
Although FN is inherited, it can be avoided in future generations by testing dogs before breeding. Identification of dogs that do not carry disease genes is the key. These "clear" dogs can be bred to any mate. With a "clear " x "clear" mating all the offspring will be "Homozygous Normal", with a "carrier" x " "clear" mating, 50% of the offspring will be "carriers" and 50% "clear". Any puppies from this combination will need to be tested prior to breeding to ascertain their status and a safe mating planned.
The OptiGen/Antagene FN test is a
DNA-based test that accurately diagnoses a fatal kidney disease that
occurs in Cocker Spaniels. The test also detects CARRIERS of this
disease and clears dogs that are genetically NORMAL.
Familial Nephropathy (FN) has been referred to in several ways:
kidney failure, fatal renal disease, juvenile nephropathy, renal
cortical hypoplasia, hereditary nephritis (HN), Autosomal Hereditary
Recessive Nephropathy (AHRN) in canines and Alport's Syndrome in
humans.
FN is inherited in an autosomal recessive pattern in the cocker spaniel. This means the gene mutation responsible for FN is located on an autosome (that is, a chromosome that is not a sex chromosome) and FN disease results when the gene mutation is passed to the offspring by both the mother and the father. FN disease is a juvenile-onset fatal kidney (renal) failure recognized in cocker spaniels worldwide for more than 50 years. The renal disease caused by FN invariably is progressive and ultimately fatal; however, the rate of disease progression observed in affected dogs is more rapid in some individuals than in others. Dogs with FN typically develop chronic renal failure between 6 months and 2 years of age, with eventual and sometimes rapid destruction of both kidneys. The early clinical signs are the same as those associated with chronic renal failure due to any other cause. These include excessive water consumption, excessive urine volume, reduced growth rate or weight loss, poor quality hair coat, reduced appetite, and vomiting. Persistent high levels of protein in the urine of a young cocker spaniels most often proves to be due to FN.
Early in the
disease course, a diagnosis can be difficult.
Definitive clinical diagnosis can require
examination of kidney tissue after death. The FN
genetic test solves this problem immediately since
presence of the FN gene mutation is accomplished by
testing a DNA sample. This result gives the owner
immediate diagnostic information and aides in making
decisions for the affected dog and for breeding
strategies.
Because the OptiGen/Antagene FN test is a mutation-based gene test, it accurately and specifically identifies normal dogs, carriers (heterozygous dogs) and affected's.
To date, no Powerscourt dog has sired FN or any bitch produced puppies affected with FN. Thanks to our clear test results we now know that we couldn't have bred affected dogs anyway!
The careful examination of pedigrees, with safe mating's planned has helped us ensure our dogs/puppies are free of FN, however this has always been a "by the grace of God" system and we are now delighted that a DNA test is available.
For our FN test results please click here! |
|
When purchasing a puppy ask whether the
parents have been OptiGen/Antagene tested for FN or are from parents who are genetically
Clear due to having two Clear parents? At least
one of the parents should be "Clear" to ensure that no affected puppies
are produced.
There should be no excuse for not testing breeding stock! |
| Two companies are licensed
to perform FN testing,
OptiGen in the US and
Antagene in France. The OptiGen/Antagene FN test is performed on a small sample of blood from the dog. The DNA is analysed for the gene mutation. The result of the test is a genotype - a fingerprint - that allows separation of dogs into three groups for Cocker Spaniels: Clear, Carrier & Affected. |
|
|
||||||||||||||||||||||||||||||||||||||||||||
| Enter Main Powerscourt Site | Home | Links| Breed Information | Questions To Ask | Choosing A Puppy | Are You Ready For A Dog | Puppy Farmers | Good Breeders | PRA | FN |FAQ |
© Powerscourt Cockers 2000 -
2008.
