Hemoglobin D (Hb D) is not a common disease but it when it does rear its ugly head it usually does so in India, Pakistan or Iran. It was first discovered in 1951 and differs from the other hemoglobin diseases by producing clinically significant conditions like sickle cell anemia and chronic hemolytic anemia of moderate severity (Desai 2004)
Hb D usually presents with a mild hemolytic anemia and a mild to moderate splenomegaly. Differentiating Hb D with other hemoglobin diseases is usually done by the zero thalassemia and the fact that it has also been reported to be associated with hematological malignancies. (Desai 2004 pg 13)
The disease itself is relatively rare and rather difficult to study due to its rarity. When it is found it is normally done so in north west India or additionally in Pakistan, Iran and other Asian countries such as Thailand. A common variation of the Hb D has been named Hb D-Punjab due to its occurrences in the Punjab region.
Basic biochemical properties for Hb D include the normal Hb properties with a substitution of the G AA C AA substitution at condon 121. In addition to that substitution, there is the -28 (A¡uG) mutation for the thalassemia alleles. One recent study shows that the Hb D-Punjab version can also be associated with haplotype.
A-Globin gene haplotype analysis demonstrated, for the first time, that all these Asian AD-Punjab globin genes were associated with haplotype [-++-+++], previously undescribed in other populations. (Fucharoen 2002 pg 261)
Fucharoen's study showed that finding of Hb D-Punjab in Thailand is compatible either with an independent origin of this abnormal hemoglobin or a spread of the Hb D-Punjab gene with a single origin among Asians. (Fuchareon 2002 ab)
Desai stated that, The main differential for homozygous Hb D disease is Hb D-beta zero thalassemia. Hb D has also been reported to be associated with hematological mali...