Complex interaction of Hb Hekinan [alpha27(B8) Glu-Asp] and Hb E [beta26(B8) Glu-Lys] with a deletional alpha-thalassemia 1 in a Thai family.

Abstract

Hemoglobin (Hb) Hekinan (alpha27; Glu-Asp) is a rare alpha-chain variant found mainly in Japanese and Chinese whereas Hb E (beta26; Glu-Lys) is common among Southeast Asians. We report a hitherto undescribed condition in which these two variants co-segregate. The proband was a 25-yr-old Thai woman who was encountered with the presence of mild hypochromic microcytosis with Hb 8.2 g/dL, hematocrit (Hct) 26.0%, Mean Corpuscular Value (MCV) 68.6 fL, Mean Corpuscular Hemoglobin (MCH) 21.6 pg and Mean Corpuscular Hemoglobin Concentration (MCHC) 31.5 g/dL. Although Hb electrophoresis at alkaline pH did not show any abnormal band except Hb E in addition to Hb A, high performance liquid chromatography analysis revealed abnormal peaks at the Hb A and Hb E positions. DNA analysis of the proband revealed a GAG-GAT mutation at codon 27 of the minor alpha1-globin gene for Hb Hekinan in trans to the South-east Asian (SEA) deletional alpha-thalassemia 1 determinant and a GAG-AAG mutation at codon 26 of the beta-globin gene for Hb E. She was therefore a triple heterozygote for these three anomalies. Family study identified that her mother was a double heterozygote for Hb Hekinan and Hb E without alpha-thalassemia whereas her father was a classical Hb H disease patient. The genotype-phenotype relationship observed in this Thai family with complex hemoglobinopathies is presented and a simple DNA assay based on the polymerase chain reaction methodology for rapid diagnosis of Hb Hekinan is described.

• Authors: Supan Fucharoen, Yossombat Changtrakun, Thawalwong Ratanasiri, Goonnapa Fucharoen, Kanokwan Sanchaisuriya
• Journal: European journal of haematology (Eur J Haematol) Vol. 70 Issue 5 Pg. 304-9 (May 2003) ISSN: 0902-4441 [Print] England
• PMID: 12694166 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Hemoglobins, Abnormal
• hemoglobin Hekinan
• DNA
• Hemoglobin E
• Hemoglobin H

Topics

• Adult
• Base Sequence
• DNA (genetics)
• DNA Mutational Analysis
• Female
• Gene Deletion
• Genotype
• Hemoglobin E (genetics)
• Hemoglobin H (genetics)
• Hemoglobins, Abnormal (genetics)
• Heterozygote
• Humans
• Male
• Phenotype
• Point Mutation
• Polymerase Chain Reaction (methods)
• Polymorphism, Restriction Fragment Length
• Thailand
• alpha-Thalassemia (blood, genetics)