A Novel β-Globin Variant, Hb Raklev [β 75(E19) HBB:c.227T> A (Leu→Gln)]

We present a new hemoglobin variant, Hb Raklev, characterized by the substitution of leucine with glutamine at position 75 in the beta-globin chain. This variant was discovered inadvertently during an HbA(1c) evaluation using high performance liquid chromatography in a symptomless 54-year-old Caucasian woman, with the same variant also identified in her 16-year-old daughter. Purification of the hemoglobin revealed possibly diminished 2,3-bisphosphoglycerate (2,3-BPG) sensitivity, which may result in heightened oxygen affinity. Notably, two variants have been previously documented at this location: the unstable Hb Atlanta and the high-affinity Hb Pasadena.

Automated summary

A new hemoglobin variant, Hb Raklev, characterized by the substitution of leucine with glutamine at position 75 in the beta-globin chain, was discovered. The variant showed possibly diminished 2,3-bisphosphoglycerate (2,3-BPG) sensitivity, resulting in heightened oxygen affinity. Two other variants have been reported at this location previously.