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
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
- 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
- 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
- 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
Created on 2010-06-16 16:13:15,
Last reviewed on 2022-04-08 10:49:52 (Show full history)
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