Over 1000 different mutations of the globin chains of the human hemoglobin molecule have been discovered. They are classified according to the type of mutation (eg, insertion, deletion, base change), the affected globin subunit (eg, alpha chain, beta chain), and by the clinical and hematologic phenotype. Abnormal hemoglobins can be detected by a number of protein-based and DNA-based methods. High frequency mutations are: HbS, C, E and low frequency mutations are HbDLosAngeles, HbG-Philadelphia, Hb Hasharon. Hb H is composed of a tetramer of normal Beta chains in which there is markedly decreased production of normal alpha chain. Other abnormal hemoglobines are: Hb Koln (ustable hemoglobins), Hb Chesapeake (high oxygen affinity hemoglobins), Hb Kansas (Low oxygen affinity hemoglobins), Hb M (methemoglobin in which heme iron is locked in the ferric form), Hb constant spring and Hb O-Arab.
Lab tests:
CBC and Automated Differential
Blood Smear with Interpretation
Iron and TIBC
Hemoglobin electrophoresis
DNA testing (Prenatal diagnosis)
References:
- Disorders of Hemoglobin: Genetics, Pathophysiology, Clinical Management, Forget BG, Higgs DR, Nagel RL, et al. (Eds), Cambridge University Press, UK 1999.
- http://globin.cse.psu.edu (Accessed on April 02, 2010).
- Charache S, Weatherall DJ, Clegg JB. Polycythemia associated with a hemoglobinopathy. J Clin Invest 1966; 45:813.
