Carrier Detection in X-linked Becker Muscular Dystrophy by Muscle Provocation Test (MPT)

The muscle provocation test (MPT: 40 min of strenuous exercise on a bicycle ergometer) is a sensitive method for the detection of carriers of Duchenne muscular dystrophy. The diagnostic applicability of MPT for carrier detection in X-linked Becker muscular dystrophy is demonstrated. Obligate carriers with mean creatine kinase (CK) values on repeated determination within the normal range showed a greater CK elevation after MGP than control subjects. Three of seven daughters of obligate carriers with normal resting CK activity had increased CK activity after MPT. These data suggest that the use of MPT may enhance the capability to discriminate carriers for these X-linked recessive genes.