Biology: Concepts and Investigations 2nd Edition by Mariëlle Hoefnagels

Exercise 31

Springer spaniels often suffer from canine phospho-fructokinase (PFK) deficiency. The dogs lack an enzyme that is crucial in extracting energy from glucose molecules. Affected pups have extremely weak muscles and die within weeks. A DNA test is available to identify male and female dogs that are carriers. Why would breeders wish to identify carriers if these dogs are not affected?