HB Yokohama [β31(B13)LEU→PRO] Detected AS A de novo Mutation in a Yugoslavian Boy

Hb Yokohama [β31(B13)Leu→Pro] was observed in a young Yugoslavian boy as a de novo mutation. The child exhibited severe transfusion-dependent hemolytic anemia. The variant was detected and quantitated at 10.5% by reversed phase high performance liquid chromatography. In vitro globin chain synthesis showed a slight imbalance with an α/β ratio of 1.38. Structural characterization of the abnormal β chain was done by high performance liquid chroma-tographic analysis, on material obtained by high salt precipitation. The mutation was confirmed by sequencing of the amplified DNA.