IthaID: 88

Names and Sequences

Functionality: Globin gene causative mutation Pathogenicity: Pathogenic / Likely Pathogenic
Common Name: CD 26 GAG>AAG [Glu>Lys] HGVS Name: HBB:c.79G>A
Hb Name: HbE Protein Info: β 26(B8) Glu>Lys

Context nucleotide sequence:

Protein sequence:

Also known as:

Comments: β codon 26 GAC>AAG [Glu>Lys] change gives rise to HbE, which also activates a cryptic splice site at the junction of exon 1 and intron 1 that causes abnormal alternative splicing and decreased transcription of functional mRNA for the HbE globin chain. Thus the Hb E mutation is both a qualitative defect (because of the amino acid substitution in the globin chain) and a quantitative defect with a β-thalassemia phenotype (because of decreased production of the mutated globin chain). Reduced Hb E synthesis explains Hb E levels in heterozygotes of between 25% to 30%. The homozygous state (Hb EE) manifests as a mild anemia with microcytes and target cells. Coihneritance with other hemoglobin variants (e.g., Hb S, forming Hb SE disease) or beta-thalassemia alleles (i.e., Hb E-β-thalassemia) creates a wide range of clinical severities. For example, Hb E-β0-thalassemia results in symptoms more severe than Hb EE and more closely resembles the severity of β-thalassemia major, requiring regular blood transfusions.

We follow the HGVS sequence variant nomenclature and IUPAC standards.


Hemoglobinopathy Group: Thalassaemia and Structural Haemoglobinopathy
Hemoglobinopathy Subgroup: β-thalassaemia, β-chain variant
Allele Phenotype:β+
Stability: Unstable
Oxygen Affinity: N/A
Associated Phenotypes: Haemolytic anaemia [HP:0001878]
Ineffective erythropoiesis [HP:0010972]


Chromosome: 11
Locus: NG_000007.3
Locus Location: 70673
Size: 1 bp
Located at: β
Specific Location: Exon 1

Other details

Type of Mutation: Point-Mutation(Substitution)
Effect on Gene/Protein Function: Cryptic splice site (mRNA Processing), Missense codons (Protein Structure)
Ethnic Origin: SE Asian, European, Far East
Molecular mechanism: N/A
Inheritance: Recessive
DNA Sequence Determined: Yes


Disclaimer: The HPLC images are provided as an information resource only. Bio-Rad Laboratories, Inc and the ITHANET Portal disclaim responsibility and have no liability if this information is used for diagnostic or treatment purposes. D-10™ and VARIANT™ are registered trademarks of Bio-Rad Laboratories, Inc. and used with permission. Redistribution and use of the above material is allowed only with permission by Bio-Rad Laboratories, Inc. To access HPLC images and reports for different variants, use the IthaChrom tool.
ID Hb Variant Gene Instrument Method Area (%) Ret Time (min) Comments
564HbEβD-10Dual Kit Program41.22.78Association of HbE and beta-thalassaemia. [PDF]
462HbEβD-10Dual Kit Program28.82.92Association of HbE and Hb Constant Spring[PDF]
458HbEβD-10Dual Kit Program19.92.96HbE heterozygote with alpha-thal 1 heterozygote. [PDF]
433HbEβD-10Dual Kit Program29.62.96heterozygote[PDF]
335HbEβD-10Dual Kit Program87.32.87Homozygote.[PDF]
26HbEβD-10Dual Kit Program28.93.15Heterozygous[PDF]
20HbEβD-10HbA1c Program80.81.58Homozygous[PDF]
18HbEβD-10HbA1c Program31.41.59Heterozygous[PDF]
565HbEβVARIANTβ-thal Short Program473.73Association of HbE and beta-thalassaemia. [PDF]
463HbEβVARIANTβ-thal Short Program25.33.68Association of HbE and Hb Constant Spring[PDF]
459HbEβVARIANTβ-thal Short Program17.73.64HbE heterozygote with alpha-thal 1 heterozygote. [PDF]
434HbEβVARIANTβ-thal Short Program253.63heterozygote[PDF]
336HbEβVARIANTβ-thal Short Program76.43.65Homozygote.[PDF]
567HbEβVARIANT IIDual Kit Program42.62.885Association of HbE and beta-thalassaemia. [PDF]
566HbEβVARIANT IIβ-thal Short Program51.63.69Association of HbE and beta-thalassaemia. [PDF]
465HbEβVARIANT IIDual Kit Program27.22.899Association of HbE and Hb Constant Spring[PDF]
464HbEβVARIANT IIβ-thal Short Program27.13.68Association of HbE and Hb Constant Spring[PDF]
461HbEβVARIANT IIDual Kit Program18.92.91HbE heterozygote with alpha-thal 1 heterozygote.[PDF]
460HbEβVARIANT IIβ-thal Short Program19.43.68HbE heterozygote with alpha-thal 1 heterozygote.[PDF]
436HbEβVARIANT IIDual Kit Program25.92.926heterozygote[PDF]
435HbEβVARIANT IIβ-thal Short Program25.13.65heterozygote[PDF]
338HbEβVARIANT IIDual Kit Program69.42.9Homozygote.[PDF]
337HbEβVARIANT IIβ-thal Short Program69.53.64Homozygote.[PDF]
64HbEβVARIANT IIDual Kit Program - HbA1c85.91.737homozygote[PDF]
39HbEβVARIANT IIDual Kit Program22.42.969Heterozygous[PDF]
38HbEβVARIANT IIDual Kit Program27.63.65Heterozygous[PDF]
37HbEβVARIANT IIβ-thal Short Program25.13.66Heterozygous[PDF]
21HbEβVARIANT IIHbA1c Program80.11.84Homozygous[PDF]
19HbEβVARIANT IIHbA1c Program30.31.86Heterozygous[PDF]

In silico pathogenicity prediction

Sequence Viewer

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Publications / Origin

  1. Flatz G, Pik C, Sringam S, Haemoglobin E and beta-thalassaemia: their distribution in Thailand., Annals of human genetics, 29(2), 151-70, 1965 PubMed
  2. Fairbanks VF, Oliveros R, Brandabur JH, Willis RR, Fiester RF, Homozygous hemoglobin E mimics beta-thalassemia minor without anemia or hemolysis: hematologic, functional, and biosynthetic studies of first North American cases., American journal of hematology, 8(1), 109-21, 1980 PubMed
  3. Orkin SH, Kazazian HH, Antonarakis SE, Ostrer H, Goff SC, Sexton JP, Abnormal RNA processing due to the exon mutation of beta E-globin gene., Nature, 300(5894), 768-9, 1982 PubMed
  4. Kazazian HH, Waber PG, Boehm CD, Lee JI, Antonarakis SE, Fairbanks VF, Hemoglobin E in Europeans: further evidence for multiple origins of the beta E-globin gene., American journal of human genetics, 36(1), 212-7, 1984 PubMed
Created on 2010-06-16 16:13:14, Last reviewed on 2024-03-07 10:59:36 (Show full history)

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