Direct demonstration of the HB Suan-Dok mutation in the alpha 2-globin gene by restriction analysis with Sma I.

Hb Suan-Dok [alpha 2(109)(G16)Leu-greater than Arg beta 2] has an alpha-thalassemia-like effect due to low production and instability of the altered alpha-globin chain. Since the Hb Suan-Dok mutation (CTG-greater than CGG) creates a new Sma I restriction site, it was possible to diagnose the mutation by restriction analysis. The location in the alpha 2-globin gene was confirmed. The distribution of alpha-globin gene anomalies and a beta-thalassemia gene in the original family, deduced from examinations at the protein level, was verified by DNA analysis.