16-177070-C-T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2BP4_StrongBP7

The NM_000558.5(HBA1):​c.237C>T​(p.Asn79Asn) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000266 in 150,438 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: 𝑓 0.000027 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000010 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

HBA1
NM_000558.5 synonymous

Scores

2

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: -5.08

Publications

10 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: Likely_benign. The variant received -3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.76).
BP7
Synonymous conserved (PhyloP=-5.08 with no splicing effect.

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.237C>Tp.Asn79Asn
synonymous
Exon 2 of 3NP_000549.1P69905

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
HBA1
ENST00000320868.9
TSL:1 MANE Select
c.237C>Tp.Asn79Asn
synonymous
Exon 2 of 3ENSP00000322421.5P69905
HBA1
ENST00000472694.1
TSL:1
n.373C>T
non_coding_transcript_exon
Exon 1 of 2
HBA1
ENST00000487791.1
TSL:1
n.206C>T
non_coding_transcript_exon
Exon 2 of 2

Frequencies

GnomAD3 genomes
AF:
0.0000266
AC:
4
AN:
150438
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000731
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.0000149
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000697
AC:
1
AN:
143526
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.000131
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
Data not reliable, filtered out with message: AS_VQSR
AF:
0.0000102
AC:
14
AN:
1375496
Hom.:
0
Cov.:
26
AF XY:
0.00000440
AC XY:
3
AN XY:
681874
show subpopulations
African (AFR)
AF:
0.000189
AC:
6
AN:
31672
American (AMR)
AF:
0.00
AC:
0
AN:
37734
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25168
East Asian (EAS)
AF:
0.000190
AC:
7
AN:
36830
South Asian (SAS)
AF:
0.00
AC:
0
AN:
81006
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
35738
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4046
European-Non Finnish (NFE)
AF:
9.38e-7
AC:
1
AN:
1065784
Other (OTH)
AF:
0.00
AC:
0
AN:
57518
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.457
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000266
AC:
4
AN:
150438
Hom.:
0
Cov.:
31
AF XY:
0.0000273
AC XY:
2
AN XY:
73296
show subpopulations
African (AFR)
AF:
0.0000731
AC:
3
AN:
41032
American (AMR)
AF:
0.00
AC:
0
AN:
15142
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3418
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5130
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4752
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10510
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000149
AC:
1
AN:
67184
Other (OTH)
AF:
0.00
AC:
0
AN:
2046
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.463
Heterozygous variant carriers
0
1
1
2
2
3
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
Bravo
AF:
0.0000340

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.76
CADD
Benign
1.2
DANN
Benign
0.92
PhyloP100
-5.1
PromoterAI
-0.0058
Neutral

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: rs34440919; hg19: chr16-227069; API