Two New α Chain Variants: Hb Boghé [α58(E7)His→Gln, α2], a Variant on the Distal Histidine, and Hb Charolles [α03(G10)His→Tyr, α1]

Abstract

The present paper reports two new α-globin chain variants: Hb Boghé [α58(E7) His→Gln, α2] and Hb Charolles [α103(G10)His→Tyr,α1]. Hb Boghé was found in a 12-month-old girl who was treated for malignant histiocytosis at 9 months of age and received a bone marrow transplant from her sister. Hb Boghe was undetectable by isoelectrofocusing and high performance liquid chromatography of hemoglobins. It was only revealed by polyacrylamide gel electrophoresis of globin chains in the presence of urea-Triton X-100 and accounted for 10% of the total hemoglobin. Hb Charolles was detected in a 46-year-old patient who presented with microcytosis and hypochromia. It was easily detected by isoelectrofocusing and high performance liquid chromatography. Hb Charolles accounted for 11% of the total hemoglobin. Characterization of the two hemoglobin variants was achieved by DNA and restriction enzyme analyses. Oxygen equilibrium curves measured on whole blood with Hb Boghé were normal. DNA sequencing revealed the association of Hb Charolles with a common mutation of the α2 polyadenylation site: AATAAA→ AATAAG.