Duchenne muscular dystrophy (DMD), the commonest X-linked disorder, is a progressive, eventually fatal disease. With the advent of molecular genetics, the Duchenne gene and its protein product, dystrophin, have been characterised. Molecular diagnosis of DMD, identification of carriers and antenatal diagnosis are now possible. We describe here the use, in a Malaysian boy with DMD, of a recent innovation, multiplex polymerase chain reaction (PCR), to obtain molecular diagnosis by detection of dystrophin gene deletions.