GSD VII / phosphofructokinase deficiency (PFKM-related) - Deutscher Wachtelhund

What does this test examine?

This genetic test analyses the PFKM variant c.550C>T for GSD VII / phosphofructokinase deficiency in the Deutscher Wachtelhund. The condition is also referred to as GSD VII / phosphofructokinase deficiency, glycogen storage disease, GSD and a PFKM-related metabolic disease.

What does this disease mean?

GSD VII is a glycolysis and glycogen metabolism disorder in which muscle and red blood cells can be particularly vulnerable. Affected dogs can develop exercise intolerance, muscle cramps or weakness, dark urine after exertion and signs of haemolytic anaemia.

PFKM encodes muscle phosphofructokinase, a key enzyme in glycolysis. The tested stop variant disrupts energy supply in muscle cells and red blood cells, explaining exercise problems and red cell breakdown in GSD VII.

Inheritance and result

The condition follows an autosomal recessive inheritance pattern. Carriers have one copy and are usually not affected themselves; dogs with two copies develop the tested form of the disease.

• Clear: the tested variant was not detected.
• Carrier: one copy was detected; this is especially relevant for breeding plans.
• Affected: two copies were detected; this genotype causes the tested disease.

Practical value of this test

The test makes a hidden recessive risk visible before breeding decisions are made. This is practically important because carriers can look healthy, while two carriers can produce affected puppies.

• Supports breeding selection and safe mating plans.
• Helps identify hidden carriers before they are unknowingly used for breeding.
• Reduces the risk of puppies with a severe inherited metabolic disease.
• Provides clear genetic information when compatible signs or family history are relevant.