Hemoglobin D (Hb D Punjab/ Los Angeles and Hb D Iran) and Co-Inheritance with Alpha- and Beta- Thalassemia in southern Iran

Background: Hemoglobin-D (Hb D) is an uncommon structural hemoglobin variant, which is reported to be prevalent in north western India. There are only a few small series, of this entity in the literature. We report the largest single center experience on this entity from Iran. Methods: Between November 2002 and December 2010 as a result of screening premaritally for betathalassemia in Shiraz, Fars Province, Southern Iran, column chromatography, Hb electrophoresis, solubility test, and/or high performance liquid chromatography (HPLC), direct sequencing and restriction analysis were used for hemoglobinopathies and structural Hb variants. The data of 220 subjects with Hb D variants are analyzed in this report. Results: These comprised of 180 carries of Hb D; 92 cases of Hb D Punjab/Los Angeles (b121Glutamic acid®Glutamine) and 88 subjects with Hb D Iran (b 22 Glu®Gln), 3 homozygous cases for Hb D, 17 subjects with betathalassemia- Hb D, 12 with Hb D- alpha- thalassemia- 1, 3 homozygous Hb D- alpha thalassemia- 1 trait, one with Hb D Punjab - sickle cell anemia, and two with Hb D Iran/sickle cell anemia. Conclusion: The carriers of Hb D and homozygous cases for Hb D were not anemic and had normal red blood cell morphology, as they are not usually detected. If Hb D was inherited in combination with thalassemia, the subjects had mild anemia and in some of them, the spleen was palpable (1-2 cm). Co-inheritance of alpha thalassemia and Hb D resulted in the slightly higher Hb level and lower Hb D level as compared to Hb D/ betathalassemia cases (Hb D 24-37% vs 57-88%). Co inheritance of Hb D and sickle cell results was moderate to severe hemolytic anemia.