Recently, it has been suggested that all newborn male infants be screened for Duchenne muscular dystrophy (DMD) by measuring creatine phosphokinase (CPK) levels.1,2 One of the main arguments for this approach is that mothers of affected infants who have no known family history of DMD can be counseled. Current genetic counseling advice, however, is based on a theory that many DMD patients represent new mutations.3-5 Zellweger and Antonik have stated the theory when they say, "DMD is inherited as an X-linked recessive trait in two-thirds of the cases, and is due to new mutations in the rest of the cases.l