IthaID: 529


Names and Sequences

Functionality: Globin gene causative mutation Pathogenicity: Pathogenic / Likely Pathogenic
Common Name: CD 43 TTC>TTG [Phe>Leu] HGVS Name: HBA2:c.132C>G
Hb Name: Hb Hirosaki Protein Info: α2 43(CE1) Phe>Leu

Context nucleotide sequence:
CCTTCCCCACCACCAAGACCTACTT [C/G] CCGCACTTCGACCTGAGCCACGGCT (Strand: +)

Protein sequence:
MVLSPADKTNVKAAWGKVGAHAGEYGAEALERMFLSFPTTKTYLPHFDLSHGSAQVKGHGKKVADALTNAVAHVDDMPNALSALSDLHAHKLRVDPVNFKLLSHCLLVTLAAHLPAEFTPAVHASLDKFLASVSTVLTSKYR

Also known as:

Comments: The phenylalanyl side chain at the position α43 (CE1) is in close contact with the heme moiety on the side of the distal histine in helix E7. Altered heme pocket. Phe>Leu replacement changes the hydrophobic heme to the hydrophilic state, resulting in heme oxygenation and leading to the formation of an unstable haemoglobin (Hb). Extremely unstable and rapidly degraded after biosynthesis, hence not detected during routine screening. Positive heat precipitation and isopropanol tests. Presence of Heinz bodies. Initially reported in a family with congenital nonspherocytic hemolytic disease, later in additional families and as a sporadic case. Affected individuals were in heterozygous state. Autosomal dominant mode of inheritance. Differences in the clinical severity of the affected individuals, ranging from asymptomatic presentation (hypochromic and normocytic anaemia) to repeated hemolytic crises. Ameliorated after splenectomy. Also reported as a severe fetal anaemia with hydrops fetalis due to the co-inheritance of Hb Hirosaki with an α0-thalassaemia mutation (--SEA).

We follow the HGVS sequence variant nomenclature and IUPAC standards.

Phenotype

Hemoglobinopathy Group: Structural Haemoglobinopathy
Hemoglobinopathy Subgroup: α-chain variant
Allele Phenotype:Dominant
Stability: Hyperunstable
Oxygen Affinity: N/A
Associated Phenotypes: Haemolytic anaemia [HP:0001878]

Location

Chromosome: 16
Locus: NG_000006.1
Locus Location: 34024
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: Japanese, Chinese
Molecular mechanism: Altered heme pocket
Inheritance: Dominant
DNA Sequence Determined: Yes

In silico pathogenicity prediction

Publications / Origin

  1. Ohba Y, Miyaji T, Matsuoka M, Yokoyama M, Numakura H, Hemoglobin Hirosaki (alpha 43 [CE 1] Phe replaced by Leu), a new unstable variant., Biochim. Biophys. Acta , 405(1), 155-60, 1975
  2. Ohba Y, Miyaji T, Matsuoka M, Yokoyama M, Further studies on hemoglobin Hirosaki: demonstration of its presence at low concentration., Hemoglobin , 2(3), 281-6, 1978
  3. Yokoyama M, Kudo Y, Sato Y, Izumi Y, Ohba Y, Miyaji T, Clinical features and biochemical aspects of red blood cells in Hb Hirosaki., Tohoku J. Exp. Med., 133(2), 187-96, 1981
  4. Ohba Y, Yamamoto K, Hattori Y, Yamamoto K, Miyaji T, Shiosaki F, Mori H, Yamaguchi K, Takahashi M, Mizoguchi H, Further cases of Hb Hirosaki in two Japanese families., Int. J. Hematol. , 54(1), 15-23, 1991
  5. Tanaka Y, Matsui K, Matsuda K, Shinohara K, Haranob K, A family with hemoglobin Hirosaki., Int. J. Hematol., 82(2), 124-6, 2005
  6. Li Q, Li Y, Zhong M, Zhang VW, Jin W, Li S, Li L, A Rare Hb H Hydrops Fetalis Syndrome Caused by the - - Deletion in Combination with the Rare Hb Hirosaki Mutation in a Chinese Patient., Hemoglobin, 42(4), 278-280, 2018
  7. Takahata M, Ibata M, Hirano T, Iwasaki H, [Hb Hirosaki hemoglobinopathy initially suspected due to low oxygen saturation levels and abnormally low HbA1c levels]., Rinsho Ketsueki, 60(3), 213-217, 2019
Created on 2010-06-16 16:13:15, Last reviewed on 2019-06-24 12:01:21 (Show full history)

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