HBA2
  • 30
    Haplo
    Score
  • 0
    Triplo
    Score

Gene Facts External Data Attribution

HGNC Symbol
HBA2 (HGNC:4824) HGNC Entrez Ensembl OMIM UCSC GeneReviews LOVD LSDB ClinVar
HGNC Name
hemoglobin subunit alpha 2
Gene type
protein-coding gene
Locus type
gene with protein product
Previous symbols
No previous names found
Alias symbols
HBA-T2
%HI
60.06(Read more about the DECIPHER Haploinsufficiency Index)
pLI
0(Read more about gnomAD pLI score)
LOEUF
1.92(Read more about gnomAD LOEUF score)
Cytoband
16p13.3
Genomic Coordinates
GRCh37/hg19: chr16:222875-223709 NCBI Ensembl UCSC
GRCh38/hg38: chr16:172876-173710 NCBI Ensembl UCSC
MANE Select Transcript
NM_000517.6 ENST00000251595.11 (Read more about MANE Select)

Dosage Sensitivity Summary (Gene)

Dosage ID:
ISCA-11790
ClinGen Curation ID:
CCID:007272
Curation Status:
Complete
Issue Type:
Dosage Curation - Gene
Haploinsufficiency:
Gene Associated with Autosomal Recessive Phenotype (30)
Read full report...
Triplosensitivity:
No Evidence for Triplosensitivity (0)
Read full report...
Last Evaluated:
07/06/2012

Haploinsufficiency (HI) Score Details

HI Score:
30
HI Evidence Strength:
Gene Associated with Autosomal Recessive Phenotype (Disclaimer)
HI Disease:
HI Evidence Comments:
Autosomal recessive type defects (including homozygous or compound heterozygous intragenic CNCs and whole gene deletions) of HBA2 cause Alpha-thalassemia. Deletion of both α-globin genes (i.e. HBA1 and HBA2) on chromosome 16: More than 20 different deletions ranging from approximately 6 kb to more than 300 kb and removing both α-globin genes (and sometimes embryonic HBZ) have been reported. In the homozygous state these deletions result in Hb Bart syndrome. When any of these alleles occur in combination with another allele carrying a single α-globin gene deletion the result is HbH disease (GeneReviews). Hemoglobin Bart hydrops fetalis (Hb Bart) syndrome, the most severe form of α-thalassemia, is characterized by fetal onset of generalized edema, ascites, pleural and pericardial effusions, and severe hypochromic anemia, in the absence of ABO or Rh blood group incompatibility. It is usually detected by ultrasonography at 22 to 28 weeks' gestation and can be suspected in an at-risk pregnancy at 13 to 14 weeks' gestation when increased nuchal thickness, possible placental thickness, and increased cardiothoracic ratio are present. Death in the neonatal period is almost inevitable. All four α-globin alleles are deleted or dysfunctional (inactivated). Of note, in certain instances, carriers may display an α-thalassemia trait hematologic phenotype. Please see GeneReviews for more detailed information.

Triplosensitivity (TS) Score Details

TS Score:
0
TS Evidence Strength:
No Evidence for Triplosensitivity (Disclaimer)
TS Evidence Comments:
No literature identified.

Genomic View

Select assembly: (NC_000016.9) (NC_000016.10)