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: Lina Zhuang, Niren Patel, Shanequa Bryant, Abdullah Kutlar, Ferdane Kutlar, Andrew N Young
• Journal: Hemoglobin (Hemoglobin) Vol. 37 Issue 5 Pg. 481-5 ( 2013) ISSN: 1532-432X [Electronic] England
• PMID: 24006930 (Publication Type: Case Reports, Journal Article)

Chemical References

• Glycated Hemoglobin A
• Hemoglobins, Abnormal
• hemoglobin Fulton-Georgia

Topics

• Adult
• DNA Mutational Analysis
• Female
• Glycated Hemoglobin (genetics)
• Hemoglobin SC Disease (complications, genetics)
• Hemoglobins, Abnormal (genetics)
• Humans
• Point Mutation
• Sequence Deletion
• alpha-Thalassemia (complications, genetics)