A Rare Alpha Globin Chain Variant Hemoglobin Fontainebleau Poses Diagnostic Challenges by Yielding Different Results in Two Different HPLC Systems

Alpha globin chain variants constitute a very small fraction of the total hemoglobinopathy cases. Their rarity and the often-unfamiliar elution times/patterns in high performance liquid chromatography (HPLC) that mimic those of normal hemoglobin (Hb) fractions and/or known beta globin variants, render their primary diagnosis difficult. We describe here Hb Fontainebleau, a rare alpha globin chain variant, in an adult female that eluted in the HbA2 window in a less commonly used HPLC platform, Lifotronic H8, thereby causing difficulties in the diagnosis. The matter was resolved by running the sample on a more commonly used platform wherein the abnormal Hb yielded a familiar elution time and pattern known to be associated with Hb Fontainebleau. This was further confirmed by gene sequencing which showed a Codon 21 (G◊C); HBA2:c.64G > C (or HBA1) mutation. A literature search failed to reveal any published case of the unique elution pattern of Hb Fontainebleau on Lifotronic H8 HPLC platform and the associated diagnostic challenges. An increasing use of the newer HPLC platforms calls for greater awareness of these issues.