Genes in panel
STRs in panel
Prev Next
Regions in panel
Prev Next

Cytopenias and congenital anaemias

Gene: HBA2

Green List (high evidence)

HBA2 (hemoglobin subunit alpha 2)
EnsemblGeneIds (GRCh38): ENSG00000188536
EnsemblGeneIds (GRCh37): ENSG00000188536
OMIM: 141850, Gene2Phenotype
HBA2 is in 6 panels

4 reviews

Arianna Tucci (Genomics England Curator)

Green List (high evidence)

There are two alpha globin genes (HBA1 and HBA2), which are encoded in tandem on chromosome 16. Different Mutations in HBA1/HBA2 are associated with different α-thalassemias and different mode of inheritance: 1) α-thalassemia silent carrier: deletion/mutation that leads to loss of 1 α-globin gene (either HBA1 or HBA2) 2) α-thalassemia trait: deletion/mutations that leads to the loss of 2 α-globin genes either in cis (--/αα) or in trans (-α/-α); 3) Hemoglobin H disease is caused by contiguous gene deletion of HBA1 and HBA2 genes on one chromosome, and a defect (deletional / inactivating small indel /single nucletide variant), in either HBA1 or HBA2 on the other chromosome; 4) 'homozygous alpha-thalassemia' (fatal hydrops fetalis): usually caused by deletions on both chromosomes, leading no/little production of alpha globin and death in utero. The phenotypes relevant to this panel are the α-thalassemia trait and the Hemoglobin H disease. Mostly caused by deletions but rare cases of small indels or point mutations leading to decreased production of the alpha globin chans have been described (16798638, 15481890, 15182057 for example)
Created: 11 Mar 2017, 8:56 p.m.
Comment on mode of inheritance: see comment above
Created: 10 Mar 2017, 4:30 p.m.

Mode of inheritance
BOTH monoallelic and biallelic, autosomal or pseudoautosomal

Phenotypes
Heinz body anemias, 140700; Hemoglobin H disease, nondeletional 613978, alpha thalassemia

Mode of pathogenicity
Other

Sarah Leigh (Genomics England Curator)

Comment on mode of inheritance: Monoallelic inheritance reported for Heinz body anemia,140700, no information provided in OMIM for the other phenotypes
Created: 9 Mar 2017, 5:05 p.m.

Louise Daugherty (Genomics England Curator)

Comment on list classification: Needs further discussion with clinical team
Created: 2 Mar 2017, 2:40 p.m.

BRIDGE consortium (NIHRBR-RD)

Green List (high evidence)

Mode of inheritance
BOTH monoallelic and biallelic, autosomal or pseudoautosomal

Phenotypes
Globin Disorder

Variants in this GENE are reported as part of current diagnostic practice

Details

Mode of Inheritance
BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Sources
  • Expert Review Green
  • Radboud University Medical Center, Nijmegen
Phenotypes
  • Globin Disorder
  • Erythrocytosis
  • Heinz body anemia,140700
  • Hemoglobin H disease, nondeletional, 613978
  • Hypochromic microcytic anemia
  • Thalassemia, alpha-, 60413
Tags
cnv structural-variant
OMIM
141850
Clinvar variants
Variants in HBA2
Penetrance
Complete
Mode of Pathogenicity
Other - please provide details in the comments
Panels with this gene

History Filter Activity

14 Mar 2017, Gel status: 4

Set mode of pathogenicity

Ellen McDonagh (Genomics England Curator)

Mode of pathogenicity for HBA2 was changed to Other - please provide details in the comments

11 Mar 2017, Gel status: 4

panel promoted to version 1

Arianna Tucci (Genomics England Curator)

Promoted to V1 on 11 March 2017, after internal review and discussion with the clinical team.

10 Mar 2017, Gel status: 4

Gene classified by Genomics England curator

Arianna Tucci (Genomics England Curator)

This gene has been classified as Green List (High Evidence).

10 Mar 2017, Gel status: 4

Gene classified by Genomics England curator

Arianna Tucci (Genomics England Curator)

This gene has been classified as Green List (High Evidence).

10 Mar 2017, Gel status: 4

Set Mode of Inheritance

Arianna Tucci (Genomics England Curator)

Mode of inheritance for HBA2 was changed to BOTH monoallelic and biallelic, autosomal or pseudoautosomal

10 Mar 2017, Gel status: 4

Gene classified by Genomics England curator

Arianna Tucci (Genomics England Curator)

This gene has been classified as Green List (High Evidence).

9 Mar 2017, Gel status: 2

Set Mode of Inheritance

Sarah Leigh (Genomics England Curator)

Mode of inheritance for HBA2 was changed to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted

2 Mar 2017, Gel status: 2

Set Phenotypes

Louise Daugherty (Genomics England Curator)

Phenotypes for HBA2 were set to Globin Disorder; Erythrocytosis;Heinz body anemia,140700;Hemoglobin H disease, nondeletional, 613978;Hypochromic microcytic anemia;Thalassemia, alpha-, 60413

2 Mar 2017, Gel status: 2

Gene classified by Genomics England curator

Louise Daugherty (Genomics England Curator)

This gene has been classified as Amber List (Moderate Evidence).

17 Feb 2017, Gel status: 0

Created

Louise Daugherty (Genomics England Curator)

HBA2 was created by LouiseD

17 Feb 2017, Gel status: 1

Added New Source

Louise Daugherty (Genomics England Curator)

HBA2 was added to Cytopaenias and congenital anaemiaspanel. Sources: Radboud University Medical Center, Nijmegen