There may be suspicions of Duchenne raised by one of the following signs (even when there is no family history of Duchenne):

• Development and/or speech delay
• Problems with muscle function, with the Gowers’ sign (Figure 2) being the classical sign of Duchenne
• Enlarged calf muscles (called “pseudohypertrophy”)
• Elevated CK and/or increase in transaminases, or liver enzymes AST and ALT in blood tests

Although suspicion can be raised in a variety of ways, figure 3 can help to describe the steps taken in diagnosing Duchenne.