Hemoglobin 2014 ;38(6):447-8
Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences , Hamilton, Ontario , Canada .
The -83 (G > A) mutation of the β-globin gene promoter (HBB: c.-133G > A) was first reported in an adult male patient with mild thalassemic indices, suggesting that this may be a mild β(+)-thalassemia (β(+)-thal) allele. In this report, we present data from several patients who are simple heterozygotes for the -83 mutation, or compound heterozygotes for -83 and Hb S (HBB: c.20A > T) or β-thal. These cases illustrate that the -83 sequence variant is not associated with a thalassemic phenotype. This has important implications for carrier screening and genetic counseling, particularly since the -83 mutation is relatively common in African and Hispanic populations.