Combined alpha-thalassemia and Hemoglobin J-Iran [beta 77 His --> Asp]. A Family Study in southern Iran

ABSTRACT

We report a 23-year-old man and three members of his family with Hb J-Iran confirmed by electrophoresis, chain separation by high performance liquid chromatography and sequencing. Alpha thalassemia was also confirmed in two family members. The substitution at beta 77 led to a higher negative charge of the beta J-Iran subunit, which enhanced its electrostatic attraction for the normal positively-charged alpha subunit. Therefore, more Hb J-Iran than Hb A forms in the red blood cells of heterozygotes. In alpha -thalassemia, the more attractive beta J-Iran subunit out-competes beta A subunits in forming assemblies with deficient alpha subunits, so even more Hb J-Iran was formed