rs28928878

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM2PM5PP3_StrongPP5_Very_Strong

The NM_000558.5(HBA1):​c.179G>A​(p.Gly60Asp) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G60V) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 31)
Exomes 𝑓: 0.0000042 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

HBA1
NM_000558.5 missense

Scores

10
6
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6O:1

Conservation

PhyloP100: 6.10

Publications

31 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: Pathogenic. The variant received 16 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr16-177011-G-C is described in ClinVar as Pathogenic. ClinVar VariationId is 993066.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.995
PP5
Variant 16-177012-G-A is Pathogenic according to our data. Variant chr16-177012-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 15849.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HBA1NM_000558.5 linkc.179G>A p.Gly60Asp missense_variant Exon 2 of 3 ENST00000320868.9 NP_000549.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HBA1ENST00000320868.9 linkc.179G>A p.Gly60Asp missense_variant Exon 2 of 3 1 NM_000558.5 ENSP00000322421.5

Frequencies

GnomAD3 genomes
Cov.:
31
GnomAD4 exome
Data not reliable, filtered out with message: AS_VQSR
AF:
0.00000420
AC:
5
AN:
1190478
Hom.:
0
Cov.:
17
AF XY:
0.00000335
AC XY:
2
AN XY:
596968
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
27750
American (AMR)
AF:
0.00
AC:
0
AN:
36262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
23984
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35250
South Asian (SAS)
AF:
0.0000129
AC:
1
AN:
77576
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
34690
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
3702
European-Non Finnish (NFE)
AF:
0.00000111
AC:
1
AN:
900002
Other (OTH)
AF:
0.0000585
AC:
3
AN:
51262
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.405
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
31
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:6Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

alpha Thalassemia Pathogenic:2
May 29, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: HBA1 c.179G>A (p.Gly60Asp) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 135930 control chromosomes. c.179G>A has been reported in the literature in multiple individuals affected with Alpha Thalassemia (example, Bayat_2013, Tamaddoni_2009). These data indicate that the variant is very likely to be associated with disease. A different variant affecting the same codon has been classified as pathogenic by our lab (c.178G>C, p.Gly60Arg), supporting the critical relevance of codon 60 to HBA1 protein function. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 23402770, 19373587). ClinVar contains an entry for this variant (Variation ID: 15849). Based on the evidence outlined above, the variant was classified as pathogenic. -

Mar 02, 2017
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not provided Pathogenic:2
Mar 19, 2019
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not found in the total gnomAD dataset, and the data is high quality (0/165308 chr). Found in at least one symptomatic patient. Predicted to have a damaging effect on the protein. Occurs in multiple cases with a recessive pathogenic variant in the same gene. Assessment of experimental evidence suggests this variant results in abnormal protein function. -

Jun 18, 2017
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hemoglobin H disease, nondeletional Pathogenic:1
Jul 20, 2016
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

alpha Thalassemia;C0700299:Heinz body anemia;C3161174:Hemoglobin H disease;C4693798:Methemoglobinemia, alpha type;C4693823:Erythrocytosis, familial, 7 Pathogenic:1
Jun 05, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

HEMOGLOBIN ADANA 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
Pathogenic
1.0
BayesDel_addAF
Pathogenic
0.52
D
BayesDel_noAF
Pathogenic
0.51
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.45
T;.
Eigen
Uncertain
0.27
Eigen_PC
Uncertain
0.26
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Benign
0.79
T;T
M_CAP
Pathogenic
0.94
D
MetaRNN
Pathogenic
1.0
D;D
MetaSVM
Pathogenic
0.99
D
PhyloP100
6.1
PrimateAI
Uncertain
0.68
T
PROVEAN
Pathogenic
-6.5
D;D
REVEL
Pathogenic
0.92
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0
D;D
Vest4
0.96
MutPred
0.99
Gain of ubiquitination at K62 (P = 0.0525);.;
MVP
1.0
ClinPred
1.0
D
GERP RS
4.3
PromoterAI
0.047
Neutral
Varity_R
0.98
gMVP
0.99
Mutation Taster
=6/94
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs28928878; hg19: chr16-227011; API