title: Non-thalassemic phenotype associated with the -83 (G > A) mutation of the β-globin gene promoter (HBB: c.-133G > A).
abstract: 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.
authors.affiliation: Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences , Hamilton, Ontario , Canada .
authors.forename: John S
authors.initials: JS
authors.lastname: Waye
authors.forename: Barry
authors.initials: B
authors.lastname: Eng
authors.forename: Meredith
authors.initials: M
authors.lastname: Hanna
authors.forename: Betty-Ann
authors.initials: BA
authors.lastname: Hohenadel
authors.forename: Lisa N
authors.initials: LN
authors.lastname: Nakamura
authors.forename: Lynda
authors.initials: L
authors.lastname: Walker
mesh_terms: D000328:Adult; D006451:Hemoglobin, Sickle / Q000235:genetics; D006801:Humans; D008297:Male; D017354:Point Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics*; D013789:Thalassemia; D055544:beta-Globins / Q000235:genetics*
chemical_list: D006451:Hemoglobin, Sickle; D055544:beta-Globins
keywords: Pathogenicity; phenotype; promoter mutation