title: Hb Fulton-Georgia [α20(B1)His→Pro; HBA1: c.62A>C]: a new α-globin variant coinherited with α-thalassemia-2 (3.7 kb deletion) and Hb SC disease.
abstract: We report a novel hemoglobin (Hb) variant that we named Hb Fulton-Georgia, caused by a point mutation in exon 1/codon 20 of the α-globin gene [α20(B1)His→Pro; HBA1: c.62A>C]. This α chain variant was identified in an adult African-American female with Hb SC disease who was also heterozygous for the α-thalassemia-2 (α-thal-2) (3.7 kb deletion or αα/-α(3.7)). The Hb Fulton-Georgia mutation was located on the intact α1-globin gene not involved by α-thal-2. Molecular models indicated that the α20 residue of Hb Fulton-Georgia was the first amino acid of the B helix, and was not involved in α1/β1 or α1/β2 contacts in Hb S [β6(A3)Glu→Val; HBB: c.20A>T] or Hb C [β6(A3)Glu→Lys; HBB: c.19G>A] tetramers. Furthermore, the histidine→proline substitution at α20 did not disrupt the helical structure. High performance liquid chromatography (HPLC) detected Hb Fulton-Georgia in 16.0% of total Hb, consistent with inheritance on the α1 gene. Coinheritance of Hb Fulton-Georgia, heterozygous α-thal-2 and Hb SC disease was associated with a mild phenotype, consisting of microcytosis and anisocytosis, but no anemia or other hematological abnormality.
authors.affiliation: Department of Medicine, Georgia Health Sciences University/Medical College of Georgia , Augusta, Georgia, USA.
authors.forename: Lina
authors.initials: L
authors.lastname: Zhuang
authors.forename: Niren
authors.initials: N
authors.lastname: Patel
authors.forename: Shanequa
authors.initials: S
authors.lastname: Bryant
authors.forename: Abdullah
authors.initials: A
authors.lastname: Kutlar
authors.forename: Ferdane
authors.initials: F
authors.lastname: Kutlar
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Young
mesh_terms: D000328:Adult; D004252:DNA Mutational Analysis; D005260:Female; D006442:Glycated Hemoglobin / Q000235:genetics*; D006450:Hemoglobin SC Disease / Q000150:complications / Q000235:genetics; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006801:Humans; D017354:Point Mutation; D017384:Sequence Deletion; D017085:alpha-Thalassemia / Q000150:complications / Q000235:genetics
chemical_list: D006442:Glycated Hemoglobin; D006455:Hemoglobins, Abnormal; C587570:hemoglobin Fulton-Georgia