Abstract

The PKU sample, if taken after the 3rd day, is suitable for Duchenne muscular dystrophy screening using creatine phosphokinase (CPK) levels. 101 babies (53 girls and 48 boys) had CPK levels measured on filter paper blood specimens taken by heel prick on the 1st and 4th days of life. The method used was that described by Zellweger and Antonik (1975). The CPK levels were markedly raised on the 1st day of life but by the 4th they had reduced to within 3 times the upper limit of the normal range for adults. 10,000 boys were then screened for Duchenne muscular dystrophy using the PKU sample, and 2 cases were found.