IthaID: 628

Names and Sequences

Functionality: Globin gene causative mutation Pathogenicity: Pathogenic / Likely Pathogenic
Common Name: CD 79 GCG>GGG [Ala>Gly] HGVS Name: HBA2:c.239C>G
Hb Name: Hb J-Singapore Protein Info: α2 79(EF8) Ala>Gly

Context nucleotide sequence:

Protein sequence:

Also known as:

Comments: Rare, fast moving variant comprising two amino acid substitutions; asparagine to aspartic acid at position α78 (α78(EF7)Asn>Asp) and alanine to glycine at position α79 (α79(EF8)Ala>Gly). The absence of DNA evidence for the α78 (Asn>Asp) substitution means that the deamidation happens at the protein level. On CE electrophoregram, Hb J-Singapore presents in the same migration time of Hb J-Buda and Hb Bart’s (γ4). The HPLC patterns of Hb J-Singapore and Hb J-Buda are similar. Initially reported in a Malaysian family (n 4) living in Singapore [PMID: 5085670], as well as in a Thai pregnant woman during antenatal screening [J Med Assoc Thai 2018; 101 (2): 275-8]; heterozygotes are asymptomatic.

We follow the HGVS sequence variant nomenclature and IUPAC standards.


Hemoglobinopathy Group: Structural Haemoglobinopathy
Hemoglobinopathy Subgroup: α-chain variant
Allele Phenotype:N/A
Stability: N/A
Oxygen Affinity: N/A
Associated Phenotypes: N/A


Chromosome: 16
Locus: NG_000006.1
Locus Location: 34131
Size: 1 bp
Located at: α2
Specific Location: Exon 2

Other details

Type of Mutation: Point-Mutation(Substitution)
Effect on Gene/Protein Function: Missense codons (Protein Structure)
Ethnic Origin: Malay, Thai
Molecular mechanism: N/A
Inheritance: Recessive
DNA Sequence Determined: Yes

In silico pathogenicity prediction

Sequence Viewer

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Publications / Origin

  1. Blackwell RQ, Boon WH, Liu CS, Weng MI, Hemoglobin J Singapore: alpha 78 Asn--Asp; alpha 79 Ala--Gly., Biochim. Biophys. Acta , 278(3), 482-90, 1972 PubMed
Created on 2010-06-16 16:13:16, Last reviewed on 2022-12-12 14:26:33 (Show full history)

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