Activity of creatine kinase in sera from healthy women,carriers of Duchenne muscular dystrophy and cord blood,determined by the “European” recommended method with NAC-EDTA activation

Creatine kinase activity has been measured at 37°C in sera from healthy women, carriers of Duchenne muscular dystrophy and cord blood, with activation by N-acetyl cysteine (NAC) and EDTA as recommended by several European committees on standardisation. The upper limit of the reference range for healthy women was found to be 170 U/1. The distributions of creatine kinase activities in healthy and carrier women have been used to calculate probability of carrier status as a function of creatine kinase activity. Although the range of creatine kinase activities in normal cord blood is wide, the data provide a basis for interpretation when Duchenne muscular dystrophy is suspected.