IthaID: 485
Names and Sequences
| Functionality: | Globin gene causative mutation | Pathogenicity: | N/A |
|---|---|---|---|
| Common Name: | CD 23 GAG>AAG [Glu>Lys] | HGVS Name: | HBA2:c.70G>A |
| Hb Name: | Hb Chad | Protein Info: | α2 23(B4) Glu>Lys |
Context nucleotide sequence:
GGGTAAGGTCGGCGCGCACGCTGGC [G/A] AGTATGGTGCGGAGGCCCTGGAGAG (Strand: +)
Protein sequence:
MVLSPADKTNVKAAWGKVGAHAGKYGAEALERMFLSFPTTKTYFPHFDLSHGSAQVKGHGKKVADALTNAVAHVDDMPNALSALSDLHAHKLRVDPVNFKLLSHCLLVTLAAHLPAEFTPAVHASLDKFLASVSTVLTSKYR
Also known as: Hb E-Keelung
Comments: Hb Chad presented increased oxygen affinity 20% in a Japanese male [PMID:6689417]. The missense mutation GAG>AAG [Glu>Lys] at codon 23, also found in the context of a −α3.7 thalassaemia chromosome [IthaID:3915]. A recent report [PMID:35059272] reveals that the G>A substitution is located on codon 23 of the ΗΒΑ2.
We follow the HGVS sequence variant nomenclature and IUPAC standards.
Phenotype
| Hemoglobinopathy Group: | Structural Haemoglobinopathy |
|---|---|
| Hemoglobinopathy Subgroup: | α-chain variant |
| Allele Phenotype: | N/A |
| Stability: | N/A |
| Oxygen Affinity: | N/A |
| Associated Phenotypes: | N/A |
Location
| Chromosome: | 16 |
|---|---|
| Locus: | NG_000006.1 |
| Locus Location: | 33845 |
| Size: | 1 bp |
| Located at: | α2 |
| Specific Location: | Exon 1 |
Other details
| Type of Mutation: | Point-Mutation(Substitution) |
|---|---|
| Effect on Gene/Protein Function: | Missense codons (Protein Structure) |
| Ethnic Origin: | African, Chinese, Japanese |
| Molecular mechanism: | N/A |
| Inheritance: | Recessive |
| DNA Sequence Determined: | Yes |
HPLC
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To access HPLC images and reports for different variants, use the IthaChrom tool.
| ID | Hb Variant | Gene | Instrument | Method | Area (%) | Ret Time (min) | Comments | ||
|---|---|---|---|---|---|---|---|---|---|
| 93 | Hb Chad | α2 | D-10 | Dual Kit Program | 22.5 | 4.49 | Heterozygous. Clinically normal. | [PDF] | |
| 94 | Hb Chad | α2 | VARIANT | β-thal Short Program | 25.2 | 4.89 | Heterozygous. Clinically normal. | [PDF] | |
| 95 | Hb Chad | α2 | VARIANT II | β-thal Short Program | 23.6 | 4.96 | Heterozygous. Clinically normal. | [PDF] | |
| 96 | Hb Chad | α2 | VARIANT II | Dual Kit Program | 20.6 | 4.115 | Heterozygous. Clinically normal. | [PDF] |
In silico pathogenicity prediction
Note:
The impact thresholds provided in this section are based on the analyses performed in Tamana et.al. For any given tool, the impact thresholds defined for the set of variants with the same effect on function as the variant examined, are preferred over those defined for the full dataset.
Sequence Viewer
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Publications / Origin
- Boyer SH, Crosby EF, Fuller GF, Ulenurm L, Buck AA, A survey of hemoglobins in the Republic of Chad and characterization of hemoglobin Chad:alpha-2-23Glu--Lys-beta-2., Am. J. Hum. Genet. , 20(6), 570-8, 1968 PubMed
- Blackwell RQ, Weng MI, Huang JT, Haemoglobin Chad, alpha23 GLU leads to LYS, in a Chinese family in Taiwan., Trop Geogr Med , 25(4), 393-6, 1973 PubMed
- Harano T, Harano K, Shibata S, Ueda S, Mori H, Imai K, Yoshida T, Hemoglobin Chad [alpha 23 (B4) Glu replaced by Lys] discovered in a Japanese with questionable polycythemia., Hemoglobin, 7(6), 581-4, 1983 PubMed
- Yoshino K, Hirota Y, Ogawa W, Sugawara K, Kawaguchi A, Yoshino H, Ishibashi M, Yoshino G, Koga M, A case of α-chain variant hemoglobin (Hb Chad) with falsely high HbA1c levels measured by immunoassay., Diabetol Int, 13(1), 330-335, 2022 PubMed
Created on 2010-06-16 16:13:15,
Last reviewed on 2022-04-08 10:49:52 (Show full history)
| A/A | Date | Curator(s) | Comments |
|---|---|---|---|
| 1 | 2010-06-16 16:13:15 | The IthaGenes Curation Team | Created |
| 2 | 2014-03-13 09:37:28 | The IthaGenes Curation Team | Reviewed. |
| 3 | 2017-04-10 14:33:55 | The IthaGenes Curation Team | Reviewed. Mutation Names/DNA Info added. |
| 4 | 2022-04-08 10:36:46 | The IthaGenes Curation Team | Reviewed. Affected gene corrected. |
| 5 | 2022-04-08 10:49:52 | The IthaGenes Curation Team | Reviewed. Comment added. |
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IthaGenes was last updated on 2024-11-20 13:24:07