A Novel β-Globin Variant, Hb Odder [HBB: C.316C > G; CD105 (Leu > Val)]

We report the discovery of a novel beta-globin gene variant, Hb Odder, characterized by a single nucleotide substitution; HBB:c.316C > G; CD105 (Leu > Val). This variant emerged incidentally during routine HbA1c measurements for diabetes monitoring. The patient exhibited no clinical or biochemical evidence of anemia or hemolysis. Our data on this variant suggest that Hb Odder is benign, regrettably limitations in our data make formal evaluations of stability and oxygen affinity impossible; additionally this emphasizes the importance of considering hemoglobin variants in the differential diagnosis of abnormal Hb A1c levels and suggest that laboratories should use alternative methods for the correct measurement of Hb A1c when hemoglobin variants interfere with diabetes monitoring. Notably, three other mutations have been described at codon 105 of the beta globin chains and correspond to three Hb variants with different characteristics: Hb South Milwaukee, Hb Bellevue IV and Hb St. George.