Analysis of the Hb M Milwaukee mutation at the DNA level.

Restriction endonuclease mapping of cellular DNA with the enzyme Sst I has been used to detect the haemoglobin (Hb) Milwaukee mutation directly. Instead of a normal 15.5 kilobase pairs (kb) fragment which contains the normal beta-globin structural genes, in heterozygous Hb M Milwaukee DNA two additional fragments of 9.0 kb and 6.5 kb were obtained that are diagnostic for this anomaly. The position of Sst I sites within the beta-globin gene region could be established.