title: Complex interaction of hemoglobin (Hb) Nakhon Ratchasima [α63(E12)Ala→Val], a novel α2-globin chain variant with Hb E [β26(B8)Glu→Lys] and a deletional α(+)-thalassemia.
abstract: OBJECTIVE
  To describe the hematological and molecular features as well as diagnostic aspects of a complex hemoglobinopathy caused by interaction of a novel α2-globin chain variant with hemoglobin (Hb) E and α(+)-thalassemia.
  
  
  METHODS
  Blood specimen of a 41-yr-old Thai man was transferred to our center for the analysis of unknown Hb variant. Hb analysis was carried out using automated high-performance liquid chromatography (HPLC) and capillary electrophoresis system. Mutation was identified by PCR and related techniques.
  
  
  RESULTS
  RBC analysis revealed a mild anemia but blood indices were within normal ranges. Hb-HPLC analysis demonstrated, in addition to the Hb E and Hb A, two abnormal peaks not fully separated from Hb A and Hb E, but capillary electrophoresis showed a pattern of Hb E heterozygote with 4.0% Hb A(2). DNA analysis of the α2 globin gene identified a novel mutation (namely Hb Nakhon Ratchasima), GCC (Ala)→GTC (Val) at codon 63 in trans to the α(+)-thalassemia (3.7-kb deletion). Association of this novel α-chain variant with β(E) globin chain leads to the formation of another novel Hb derivative with different HPLC characteristics.
  
  
  CONCLUSIONS
  Although Hb Nakhon Ratchasima might be clinically innocuous, differential diagnosis from other clinically relevant hemoglobinopathies is essential in routine setting. This could be made by using a simple PCR-restriction fragment length polymorphism assay or allele-specific PCR assay developed in this study.
authors: The Graduate School, Khon Kaen University, Khon Kaen.
authors: Hataichanok
authors: H
authors: Srivorakun
authors: Goonnapa
authors: G
authors: Fucharoen
authors: Rawiwan
authors: R
authors: Puangplruk
authors: Napat
authors: N
authors: Kheawon
authors: Supan
authors: S
authors: Fucharoen
mesh_terms: D000328:Adult; D019943:Amino Acid Substitution; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D004252:DNA Mutational Analysis; D006446:Hemoglobin E / Q000235:genetics*; D006453:Hemoglobinopathies / Q000097:blood* / Q000235:genetics*; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D008297:Male; D020125:Mutation, Missense; D016133:Polymerase Chain Reaction; D017384:Sequence Deletion; D055542:alpha-Globins / Q000235:genetics*; D017085:alpha-Thalassemia / Q000097:blood* / Q000235:genetics*
chemical_list: D006455:Hemoglobins, Abnormal; D055542:alpha-Globins; D004247:DNA; D006446:Hemoglobin E