16-176786-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_StrongPM2

The NM_000558.5(HBA1):​c.70G>T​(p.Glu24*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000671 in 149,118 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: 𝑓 0.0000067 ( 0 hom., cov: 28)
Exomes 𝑓: 0.0000014 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

HBA1
NM_000558.5 stop_gained

Scores

2
1
4

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 0.832
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.837 CDS is truncated, and there are 2 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
HBA1NM_000558.5 linkuse as main transcriptc.70G>T p.Glu24* stop_gained 1/3 ENST00000320868.9 NP_000549.1 P69905D1MGQ2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
HBA1ENST00000320868.9 linkuse as main transcriptc.70G>T p.Glu24* stop_gained 1/31 NM_000558.5 ENSP00000322421.5 P69905
HBA1ENST00000472694.1 linkuse as main transcriptn.89G>T non_coding_transcript_exon_variant 1/21
HBA1ENST00000487791.1 linkuse as main transcriptn.39G>T non_coding_transcript_exon_variant 1/21
HBA1ENST00000397797.1 linkuse as main transcriptc.-2+24G>T intron_variant 2 ENSP00000380899.1 G3V1N2

Frequencies

GnomAD3 genomes
AF:
0.00000671
AC:
1
AN:
149118
Hom.:
0
Cov.:
28
show subpopulations
Gnomad AFR
AF:
0.0000246
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AS_VQSR
AF:
0.00000140
AC:
2
AN:
1428558
Hom.:
0
Cov.:
26
AF XY:
0.00
AC XY:
0
AN XY:
709400
show subpopulations
Gnomad4 AFR exome
AF:
0.0000623
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000671
AC:
1
AN:
149118
Hom.:
0
Cov.:
28
AF XY:
0.00
AC XY:
0
AN XY:
72598
show subpopulations
Gnomad4 AFR
AF:
0.0000246
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.39
D
BayesDel_noAF
Pathogenic
0.32
CADD
Pathogenic
32
DANN
Uncertain
0.99
Eigen
Benign
0.16
Eigen_PC
Benign
-0.22
FATHMM_MKL
Benign
0.55
D
Vest4
0.46
GERP RS
1.3

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.17
Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs33939620; hg19: chr16-226785; API