IthaID: 690


Names and Sequences

Functionality: Globin gene causative mutation Pathogenicity: Benign / Likely Benign
Common Name: CD 99 AAG>GAG [Lys>Glu] HGVS Name: NM_000558.5(HBA1):c.298A>G
Hb Name: Hb Turriff Protein Info: α1 99(G6) Lys>Glu

Context nucleotide sequence:
GCTTCGGGTGGACCCGGTCAACTTC [A/G] AGGTGAGCGGCGGGCCGGGAGCGAT (Strand: +)

Protein sequence:
MVLSPADKTNVKAAWGKVGAHAGEYGAEALERMFLSFPTTKTYFPHFDLSHGSAQVKGHGKKVADALTNAVAHVDDMPNALSALSDLHAHKLRVDPVNFELLSHCLLVTLAAHLPAEFTPAVHASLDKFLASVSTVLTSKYR

Also known as: Hb Turriff-I

Comments: The lysine residue at α99(G6) is in the central cavity of the haemoglobin tetramer, situated in the region of the α1β1 contact. The Lys>Glu replacement does not appear to impair β-chain interactions. It disrupts AHSP binding, hence variant may be mildly destabilizing. Initially reported as a de novo mutation (α1 or α2) in a Scottish person during HbA1c screening (22% of the total Hb). Reported as an α1 globin gene mutation in a Japanese person with a high HbA1 level, hence called Hb Turriff-I (10.5% of the total Hb). Variant was not associated with any haematological disturbance. Normal isopropanol stability test.

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: 37994
Size: 1 bp
Located at: α1
Specific Location: Exon 2

Other details

Type of Mutation: Point-Mutation(Substitution)
Effect on Gene/Protein Function: Missense codons (Protein Structure)
Ethnic Origin: Scottish, Japanese
Molecular mechanism: Altered α1β1 interface
Inheritance: Recessive
DNA Sequence Determined: Yes

In silico pathogenicity prediction

Publications / Origin

  1. Langdown JV, Davidson RJ, Williamson D, A new alpha chain variant, Hb Turriff [alpha 99(G6)Lys----Glu]: the interference of abnormal hemoglobins in Hb A1c determination., Hemoglobin , 16(1), 11-7, 1992
  2. Harano T, Harano K, Hong YF, Than AM, Suetsugu Y, Ohba K, The mutation of Hb Turriff [alpha99(G6)Lys --> Glu (AAG --> GAG)] is carried by the alpha1-globin gene in a Japanese (Hb Turriff-I)., Hemoglobin, 27(2), 123-7, 2003
  3. Thom CS, Dickson CF, Gell DA, Weiss MJ, Hemoglobin variants: biochemical properties and clinical correlates., Cold Spring Harb Perspect Med, 3(3), a011858, 2013
Created on 2010-06-16 16:13:16, Last reviewed on 2024-04-12 10:24:54 (Show full history)

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