Serum pyruvate kinase in carriers of Duochenne muscular dystrophy.

Independent studies by two different groups (Madras and Edinburgh) have failed to confirm the suggestion that measurement of the serum level of pyruvate kinase (EC 2.7.1.40, PK) may be superior to measurement of the serum level of creatine kinase (EC 2.7.3.2, CK) for detecting female carriers of X-linked Duchenne muscular dystrophy (DMD). At present the serum level of creatine kinase remains the best test for this purpose.