[Rare hemoglobins in Togo: a 15-year study at the Lomé University Campus Hospital Center]

To identify the rare hemoglobins (Hbs) encountered in Togo and characterize their geographical and ethnic distribution and hematologic expression.

This retrospective descriptive study covers 27,530 hemoglobin electrophoresis tests performed in the department of Hematology of the Lomé Campus teaching hospital from January 1996 through December 2010, the national reference laboratory. The anomalies identified were studied with both alkaline and acid electrophoresis and high performance liquid chromatography (HPLC), all performed in Lome. Any other specialized examinations were conducted mainly at the biochemistry laboratories of either Robert Debre Hospital in Paris or Henri Mondor Hospital in Creteil (France).

During the study period, 20 cases of a rare Hb were identified, i.e., 0.07% of all Hb analyses. These rare mutants were: HbK Woolwich (10 cases, 50% of the rare Hbs); HbD Korle-Bu (7 cases, 35%); HbJ Lome, G Philadelphia, and Hb Lepore (1 case each, 5% for each). Eighteen cases were associated with Hb A. Two cases of composite rare Hb were found: HbS/HbK Woolwich and HbC/Hb D Korle-Bu. Carriers of Hb Lepore and of HbC/HbD Korle-Bu had hypochromic and microcytic anemia. HbK Woolwich was found in the Adja-Ewé and Tem-Kabyé ethnic groups, in the Maritime and Kara regions; HbD Korle-Bu, HbJ Lome, and Hb Lepore were also identified among the Adja-Ewé, and HbG Philadelphia in the Akposso ethnic group of the Plateau zone.

This study although limited to Lome, allowed us to identify the rare Hb forms observed in Togo. Other studies on a national scale will specify their real frequency.