16-177331-G-A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM1PP3_ModerateBP6

The NM_000558.5(HBA1):​c.349G>A​(p.Glu117Lys) variant causes a missense change. The variant allele was found at a frequency of 0.00000558 in 1,613,142 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E117Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000055 ( 1 hom. )

Consequence

HBA1
NM_000558.5 missense

Scores

5
8
4

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:2O:5

Conservation

PhyloP100: 4.82

Publications

3 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):
  • HBA1-related alpha thalassemia spectrum
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • alpha thalassemia spectrum
    Inheritance: SD, AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • erythrocytosis, familial, 7
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Genomics England PanelApp, ClinGen
  • unstable hemoglobin disease
    Inheritance: AD Classification: MODERATE Submitted by: ClinGen
  • 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, 14 uncertain in NM_000558.5
PP3
MetaRNN computational evidence supports a deleterious effect, 0.893
BP6
Variant 16-177331-G-A is Benign according to our data. Variant chr16-177331-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 15793.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000558.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
HBA1
NM_000558.5
MANE Select
c.349G>Ap.Glu117Lys
missense
Exon 3 of 3NP_000549.1P69905

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
HBA1
ENST00000320868.9
TSL:1 MANE Select
c.349G>Ap.Glu117Lys
missense
Exon 3 of 3ENSP00000322421.5P69905
HBA1
ENST00000472694.1
TSL:1
n.485G>A
non_coding_transcript_exon
Exon 2 of 2
HBA1
ENST00000397797.1
TSL:2
c.253G>Ap.Glu85Lys
missense
Exon 3 of 3ENSP00000380899.1G3V1N2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152160
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000811
AC:
2
AN:
246712
AF XY:
0.0000149
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000548
AC:
8
AN:
1460982
Hom.:
1
Cov.:
32
AF XY:
0.00000826
AC XY:
6
AN XY:
726774
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33466
American (AMR)
AF:
0.00
AC:
0
AN:
44662
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26104
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39654
South Asian (SAS)
AF:
0.0000696
AC:
6
AN:
86160
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53034
Middle Eastern (MID)
AF:
0.000347
AC:
2
AN:
5766
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111784
Other (OTH)
AF:
0.00
AC:
0
AN:
60352
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
2
3
4
5
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
AF:
0.00000657
AC:
1
AN:
152160
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74322
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41462
American (AMR)
AF:
0.00
AC:
0
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5170
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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

Genome 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
Alfa
AF:
0.00
Hom.:
0
ExAC
AF:
0.00000825
AC:
1

ClinVar

ClinVar submissions
Significance:Conflicting classifications of pathogenicity
Revision:criteria provided, conflicting classifications
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
1
1
not provided (2)
-
-
1
alpha Thalassemia (1)
-
1
-
not specified (1)
-
-
-
HEMOGLOBIN BUGINESE-X (1)
-
-
-
HEMOGLOBIN O (BUGINESE-X) (1)
-
-
-
HEMOGLOBIN O (INDONESIA) (1)
-
-
-
HEMOGLOBIN O (OLIVIERE) (1)
-
-
-
HEMOGLOBIN OLIVIERE (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.36
BayesDel_addAF
Pathogenic
0.30
D
BayesDel_noAF
Pathogenic
0.38
CADD
Benign
22
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.56
D
Eigen
Benign
-0.14
Eigen_PC
Benign
-0.22
FATHMM_MKL
Uncertain
0.80
D
LIST_S2
Benign
0.61
T
M_CAP
Pathogenic
0.55
D
MetaRNN
Pathogenic
0.89
D
MetaSVM
Uncertain
0.30
D
PhyloP100
4.8
PrimateAI
Benign
0.45
T
PROVEAN
Uncertain
-2.4
N
REVEL
Pathogenic
0.67
Sift
Uncertain
0.0030
D
Sift4G
Uncertain
0.046
D
Vest4
0.48
MutPred
0.77
Gain of methylation at E117 (P = 0.0062)
MVP
1.0
ClinPred
0.87
D
GERP RS
3.3
Varity_R
0.48
gMVP
0.75
Mutation Taster
=25/75
disease causing

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: rs63749882; hg19: chr16-227330; API