Fetal hydrops

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

Rebecca Foulger (Genomics England curator)

Comment when marking as ready: Rated as green, and mode of inheritance complete.
Created: 19 Dec 2016, 3:01 p.m.
Comment on mode of inheritance: Updated to biallelic based on Expert review and PMID:26757782.
Created: 19 Dec 2016, 2:54 p.m.
Comment on list classification: Updated rating from Red to Green: Three expert reviews. Although most mutations are deletions, point mutations are also reported in HBA2. After a discussion with the clinical team, it was therefore agreed to update the rating to Green.
Created: 19 Dec 2016, 2:51 p.m.
PMID:27686733 (Yang et al., 2016) report a rare case of a fetus who was compound heterozygote for Hb Zurich-Albisrieden [HBA2: c.178G > C; α59(E8)Gly→Arg (α2)] and the - -SEA α0-thal deletion. This is a rare case of Hb Bart's hydrops fetalis associated with Hb Zurich Albisrieden.
Created: 19 Dec 2016, 2:50 p.m.
PMID:26757782 (Hey et al., 2016) report a homozygous c.427T > C nucleotide substitution in a fetus presenting with Fetal hydrops.
Created: 19 Dec 2016, 2:44 p.m.
Comment on mode of pathogenicity: Almost all cases of alpha-thalassemia result from homozygous deletion of the HBA1 (OMIM:141800) and HBA2 (OMIM:141850) genes.
Created: 19 Dec 2016, 2:33 p.m.
Comment on phenotypes: Haven't included OMIM:141850 in the Phenotype list, because this is the OMIM ID for the HBA2 gene.
Created: 15 Dec 2016, 12:11 p.m.

Richard Choy (Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong)

Green List (high evidence)

Common in Southeast Asian
Created: 19 Dec 2016, 9:46 a.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Well known cause of hydrops

Publications

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

Liona Poon (The Chinese University of Hong Kong)

Green List (high evidence)

Review of parental haemoglobinoapthy pattern should review that the parents are alpha thalassaemia trait.
Created: 15 Dec 2016, 7:59 a.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Alpha thalassaemia; Hb H disease

Publications

Diana Wellesley (nhs)

Green List (high evidence)

Well known cause of hydrops.
Created: 22 Nov 2016, 10:43 a.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Alpha-thalassaemia OMIM 141850

Publications

Details

Mode of Inheritance
BIALLELIC, autosomal or pseudoautosomal
Sources
  • Expert Review Green
  • Other
Phenotypes
  • HYDROPS FETALIS, NONIMMUNE, 236750
  • NIHF
  • HYDROPS FETALIS, ALPHA-THALASSEMIA-RELATED, INCLUDED
  • Hemoglobin H disease, nondeletional, 613978
  • HEMOGLOBIN H HYDROPS FETALIS SYNDROME
  • Thalassemia, alpha-, 604131
  • Alpha thalassaemia
  • Hb H disease
Tags
monogenic-polygenic
OMIM
141850
Clinvar variants
Variants in HBA2
Penetrance
Complete
Publications
Mode of Pathogenicity
Other - please provide details in the comments
Panels with this gene

History Filter Activity

21 Dec 2016, Gel status: 4

panel promoted to version 1

Rebecca Foulger (Genomics England curator)

21 December 2016. External reviews were assessed, and panel was revised according to expert review, internal discussion and additional curation. Following internal discussion, all genes from the V1.14 'RASopathies' panel were added as green EXCLUDING NF1 and SPRED1- a cautious approach was taken because Fetal hydrops is a fetal panel. All relevant genes from the 'Mucopolysaccharideosis, Gaucher, Fabry' V1.0 panel (lysosomal storage disorders) were also added to the Fetal hydrops panel as green together with genes from the literature where there is a reasonable link between the corresponding lysosomal storage disorder (LSD) and Fetal hydrops. All PEX genes from the V1.2 'Peroxisomal disorders' panel were added as green based on a link between peroxisomal biogenesis disorders and Fetal hydrops.

19 Dec 2016, Gel status: 4

Gene classified by Genomics England curator

Rebecca Foulger (Genomics England curator)

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

19 Dec 2016, Gel status: 4

Set Mode of Inheritance

Rebecca Foulger (Genomics England curator)

Mode of inheritance for HBA2 was changed to BIALLELIC, autosomal or pseudoautosomal

19 Dec 2016, Gel status: 4

Gene classified by Genomics England curator

Rebecca Foulger (Genomics England curator)

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

19 Dec 2016, Gel status: 0

Set publications

Rebecca Foulger (Genomics England curator)

Publications for HBA2 were set to 9029003; 27862048; 11722414; 27686733; 26757782

19 Dec 2016, Gel status: 0

Set mode of pathogenicity

Rebecca Foulger (Genomics England curator)

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

15 Dec 2016, Gel status: 0

Set publications

Rebecca Foulger (Genomics England curator)

Publications for HBA2 were set to 9029003; 27862048; 11722414

15 Dec 2016, Gel status: 0

Set Phenotypes

Rebecca Foulger (Genomics England curator)

Phenotypes for HBA2 were set to HYDROPS FETALIS, NONIMMUNE, 236750; NIHF; HYDROPS FETALIS, ALPHA-THALASSEMIA-RELATED, INCLUDED; Hemoglobin H disease, nondeletional, 613978; HEMOGLOBIN H HYDROPS FETALIS SYNDROME; Thalassemia, alpha-, 604131; Alpha thalassaemia; Hb H disease

10 Oct 2016, Gel status: 0

Added New Source

Rebecca Foulger (Genomics England curator)

HBA2 was added to Fetal hydropspanel. Sources: Other

10 Oct 2016, Gel status: 0

Created

Rebecca Foulger (Genomics England curator)

HBA2 was created by rfoulger