PMC4103505_01
High-performance liquid chromatography chromatogram showing the unknown peak at retention time 2.92 minutes.
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HPLC analysis (BioRad, Beta thalassaemia short program) on the patient's blood revealed 13.8% of an unknown hemoglobin with retention time of 2.92 minutes which appeared as a hump in the peak adjoining Hb A (Figure 1).
Electropherogram of the alpha gene showing hemoglobin Fontainebleau [Alpha 21(B2) alpha2Ala>Pro].
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Molecular characterization was done by automated DNA sequencing on the ABI Prism 310 DNA sequencer (Applied Systems, Foster City, CA, USA.) showing presence of a heterozygous G>C substitution at codon 21 (alpha 2 globin gene) leading to the substitution of alanine to proline at the beginning of the beta helix in the alpha chain corresponding to Hb Fontainebleau in the index case, his mother and two sisters (Figure 2).