rs34068598

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1

The NM_000558.5(HBA1):​c.166G>A​(p.Val56Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V56G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000067 ( 0 hom., cov: 31)
Exomes 𝑓: 8.6e-7 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

HBA1
NM_000558.5 missense

Scores

1
4
13

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: -0.0380

Publications

2 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 2 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 26 uncertain in NM_000558.5

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HBA1NM_000558.5 linkc.166G>A p.Val56Ile missense_variant Exon 2 of 3 ENST00000320868.9 NP_000549.1 P69905D1MGQ2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HBA1ENST00000320868.9 linkc.166G>A p.Val56Ile missense_variant Exon 2 of 3 1 NM_000558.5 ENSP00000322421.5 P69905

Frequencies

GnomAD3 genomes
AF:
0.00000670
AC:
1
AN:
149350
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000667
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AS_VQSR
AF:
8.61e-7
AC:
1
AN:
1162080
Hom.:
0
Cov.:
17
AF XY:
0.00000171
AC XY:
1
AN XY:
585174
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
27178
American (AMR)
AF:
0.00
AC:
0
AN:
36946
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
23868
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35394
South Asian (SAS)
AF:
0.0000129
AC:
1
AN:
77648
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
35340
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
3620
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
871734
Other (OTH)
AF:
0.00
AC:
0
AN:
50352
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Data not reliable, filtered out with message: AS_VQSR
AF:
0.00000670
AC:
1
AN:
149350
Hom.:
0
Cov.:
31
AF XY:
0.0000137
AC XY:
1
AN XY:
72792
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
40224
American (AMR)
AF:
0.0000667
AC:
1
AN:
14982
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3440
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5072
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4550
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10442
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67430
Other (OTH)
AF:
0.00
AC:
0
AN:
1998
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.076
BayesDel_addAF
Uncertain
0.11
D
BayesDel_noAF
Benign
-0.090
CADD
Benign
5.1
DANN
Benign
0.91
DEOGEN2
Benign
0.12
T;.
Eigen
Benign
-1.0
Eigen_PC
Benign
-1.2
FATHMM_MKL
Benign
0.12
N
LIST_S2
Benign
0.86
D;D
M_CAP
Pathogenic
0.65
D
MetaRNN
Uncertain
0.53
D;D
MetaSVM
Uncertain
-0.11
T
PhyloP100
-0.038
PrimateAI
Benign
0.36
T
PROVEAN
Benign
-0.080
N;N
REVEL
Uncertain
0.53
Sift
Benign
0.17
T;T
Sift4G
Benign
0.33
T;T
Vest4
0.40
MutPred
0.58
Loss of methylation at K57 (P = 0.0628);.;
MVP
0.93
ClinPred
0.96
D
GERP RS
-5.1
PromoterAI
0.042
Neutral
Varity_R
0.16
gMVP
0.69

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: rs34068598; hg19: chr16-226998; API