DNA extraction and Southern blot analysis of two cases of McLeod's syndrome showed restriction fragments identical to normal controls using probes from the Xp21 (1-2) region, in contrast to striking deletions found in two other McLeod phenotypes studied in the USA. The McLeod locus is adjacent to Duchenne muscular dystrophy (DMD) and dystrophin immunocytochemistry showed that expression is normal in muscle from the two McLeod cases in spite of the mild DMD-like myopathy.