PHOSPHOFRUCTOKINASE (PFK) DEFICIENCY
WHAT IS IT?
- Phosphofructokinase (PFK) is a major regulatory enzyme found in all cells of the body, which catalyses (stimulates by means of a chemical reaction) the metabolism (conversion) of sugar into energy to maintain normal cell function.
- PFK deficiency is an enzyme storage disease which causes abnormalities in red blood cells and muscle cells.
- It is inherited in English Springer Spaniels through a single autosomal recessive trait.
WHAT ARE THE SYMPTOMS?
- A hallmark sign of this disease is intermittent dark urine (the colour ranging from orange to dark coffee-brown), and, in severe cases, pale gums (anaemia) or jaundice (yellow colouration of skin and gums), with fever and poor appetite. Clinical signs (most notably the dark urine) commonly develop following strenuous exercise, prolonged barking, or extensive panting, all of which are conditions that accelerate the destruction of red blood cells in affected dogs.
- PFK deficiency can present as anything from mild to life-threatening episodic illness. Clinical signs may be particularly noticeable in field trial/active working dogs, where weakness, exercise intolerance, muscle cramps, poor performance or even outright refusal to move, may be observed.
WHAT IS THE TREATMENT?
- It is essential to get a proper diagnosis, as PFK deficiency can sometimes be confused with autoimmune haemolytic anaemia and other acquired diseases.
- Clinical manifestations usually resolve within hours to days. While there is no actual treatment for Phosphofructokinase Deficiency, it can be successfully managed to the point that affected dogs may have a relatively normal lifespan. The most important "treatment" is managing the dog's activity and stress levels, to prevent more severe anaemia. Situations that can precipitate such crises (including strenuous exercise or stress) should be avoided. In cases where anaemia becomes critical, veterinary care is required to manage the condition until it normalises.
- A tiny change (point mutation) in the M-type phosphofructokinase gene was identified by research groups at the University of Pennsylvania, which has resulted in the availability of a genetic screening (DNA) test for PFK deficiency. This test accurately determines whether a dog is affected, a carrier, or a normal dog.
The procedure for requesting a DNA test for Phosphofructokinase (PFK) is as follows:
- The Animal Heath Trust requires blood samples - 2mls EDTA for the DNA test.
- You should make application to the AHT for the PFK test to be carried out on the AHT specified form. The .pdf form ‘Request for DNA Testing' can be downloaded from the Animal Health Trust website at http://www.aht.org.uk/. A separate form should be completed for each blood sample to be tested. Details of the cost of each test can also be found on the website.
- Further information can be obtained by emailing email@example.com or by contacting Symone Ingram (Telephone +44 (0) 1638 555621 or Fax +44 (0) 1638 555643).
- Samples should be sent together with the completed DNA Testing Form and payment for each sample to:
Genetic Services, Animal Health Trust
Suffolk CB7 7UU.
- The AHT will usually post the results to you within 4 - 6 weeks of receipt of sample.