rs34863047

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM1PM2BP4

The NM_000558.5(HBA1):​c.334G>A​(p.Ala112Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as other (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A112V) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

HBA1
NM_000558.5 missense

Scores

5
13

Clinical Significance

other no assertion criteria provided O:1

Conservation

PhyloP100: -3.84

Publications

1 publications found
Variant links:
Genes affected
HBA1 (HGNC:4823): (hemoglobin subunit alpha 1) The human alpha globin gene cluster located on chromosome 16 spans about 30 kb and includes seven loci: 5'- zeta - pseudozeta - mu - pseudoalpha-1 - alpha-2 - alpha-1 - theta - 3'. The alpha-2 (HBA2) and alpha-1 (HBA1) coding sequences are identical. These genes differ slightly over the 5' untranslated regions and the introns, but they differ significantly over the 3' untranslated regions. Two alpha chains plus two beta chains constitute HbA, which in normal adult life comprises about 97% of the total hemoglobin; alpha chains combine with delta chains to constitute HbA-2, which with HbF (fetal hemoglobin) makes up the remaining 3% of adult hemoglobin. Alpha thalassemias result from deletions of each of the alpha genes as well as deletions of both HBA2 and HBA1; some nondeletion alpha thalassemias have also been reported. [provided by RefSeq, Jul 2008]
HBA1 Gene-Disease associations (from GenCC):
  • alpha thalassemia spectrum
    Inheritance: AR, SD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
  • erythrocytosis, familial, 7
    Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
  • hemoglobin M disease
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Hb Bart's hydrops fetalis
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hemoglobin H disease
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • methemoglobinemia, alpha type
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen
  • Heinz body anemia
    Inheritance: AR Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 15 uncertain in NM_000558.5
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.29654223).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HBA1NM_000558.5 linkc.334G>A p.Ala112Thr missense_variant Exon 3 of 3 ENST00000320868.9 NP_000549.1 P69905D1MGQ2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HBA1ENST00000320868.9 linkc.334G>A p.Ala112Thr missense_variant Exon 3 of 3 1 NM_000558.5 ENSP00000322421.5 P69905

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
Data not reliable, filtered out with message: AC0;AS_VQSR
AF:
0.00
AC:
0
AN:
1460802
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
726694
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44670
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26090
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39658
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86180
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52858
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111778
Other (OTH)
AF:
0.00
AC:
0
AN:
60328
GnomAD4 genome
Cov.:
32

ClinVar

Significance: other
Submissions summary: Other:1
Revision: no assertion criteria provided
LINK: link

Submissions by phenotype

HEMOGLOBIN MOSELLA Other:1
Jul 20, 2016
OMIM
Significance:other
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.068
BayesDel_addAF
Uncertain
0.14
D
BayesDel_noAF
Uncertain
-0.030
CADD
Benign
0.16
DANN
Benign
0.86
DEOGEN2
Benign
0.20
T;.
Eigen
Benign
-1.6
Eigen_PC
Benign
-1.8
FATHMM_MKL
Benign
0.015
N
LIST_S2
Uncertain
0.88
D;T
M_CAP
Uncertain
0.25
D
MetaRNN
Benign
0.30
T;T
MetaSVM
Benign
-0.42
T
PhyloP100
-3.8
PrimateAI
Benign
0.30
T
PROVEAN
Benign
-0.60
N;N
REVEL
Uncertain
0.53
Sift
Benign
0.12
T;T
Sift4G
Benign
0.56
T;T
Vest4
0.066
MutPred
0.60
Gain of glycosylation at A112 (P = 0.0136);.;
MVP
0.99
ClinPred
0.12
T
GERP RS
-8.9
Varity_R
0.24
gMVP
0.66

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs34863047; hg19: chr16-227315; COSMIC: COSV109408735; COSMIC: COSV109408735; API