rs41321052

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 6P and 1B. PM2PP3_StrongBP6

The NM_000517.6(HBA2):​c.307A>C​(p.Ser103Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,458,060 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in UniProt.

Frequency

Genomes: not found (cov: 25)
Exomes š‘“: 0.0000014 ( 0 hom. )

Consequence

HBA2
NM_000517.6 missense

Scores

4
7
5

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: -0.811
Variant links:
Genes affected
HBA2 (HGNC:4824): (hemoglobin subunit alpha 2) 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 Uncertain_significance. Variant got 5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.977
BP6
Variant 16-173478-A-C is Benign according to our data. Variant chr16-173478-A-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1330535.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HBA2NM_000517.6 linkc.307A>C p.Ser103Arg missense_variant Exon 3 of 3 ENST00000251595.11 NP_000508.1 P69905D1MGQ2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HBA2ENST00000251595.11 linkc.307A>C p.Ser103Arg missense_variant Exon 3 of 3 1 NM_000517.6 ENSP00000251595.6 P69905

Frequencies

GnomAD3 genomes
Cov.:
25
GnomAD3 exomes
AF:
0.00000806
AC:
2
AN:
248256
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
134650
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 SAS exome
AF:
0.0000330
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000887
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1458060
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
725166
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000117
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
8.99e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
25
ExAC
AF:
0.00000828
AC:
1
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Feb 09, 2022
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Dec 01, 2022
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The frequency of this variant in the general population, 0.0000081 (2/248256 chromosomes, http://gnomad.broadinstitute.org), is uninformative in assessment of its pathogenicity. In vitro studies have shown that Hb Manitoba I is mildly unstable and has reduced dissociation (PMID: 7803274 (1994), 5452728 (1970)). Individuals heterozygous for this variant have a normal clinical presentation, with Hb Manitoba I accounting for 19% of total hemoglobin (PMID: 11791879 (2001), 7803274 (1994), 6547932 (1984), 5452728 (1970)). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded conflicting predictions that this variant is deleterious or benign. Based on the available information, we are unable to determine the clinical significance of this variant. -

alpha Thalassemia;C0700299:Heinz body anemia;C3161174:Hemoglobin H disease;C4693823:Erythrocytosis, familial, 7 Uncertain:1
Jun 11, 2024
Fulgent Genetics, Fulgent Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.32
D
BayesDel_noAF
Pathogenic
0.33
CADD
Benign
20
DANN
Uncertain
0.99
DEOGEN2
Benign
0.021
.;T
Eigen
Benign
-0.45
Eigen_PC
Benign
-0.47
FATHMM_MKL
Benign
0.17
N
M_CAP
Pathogenic
0.42
D
MetaRNN
Pathogenic
0.98
D;D
MetaSVM
Uncertain
-0.093
T
PrimateAI
Uncertain
0.58
T
PROVEAN
Uncertain
-3.8
D;D
REVEL
Uncertain
0.59
Sift
Uncertain
0.0040
D;D
Sift4G
Uncertain
0.023
D;D
Vest4
0.76
MutPred
0.96
Gain of catalytic residue at S103 (P = 0.0654);.;
MVP
1.0
MPC
1.7
ClinPred
0.82
D
GERP RS
0.32
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
gMVP
0.94

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

LitVar

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

Other links and lift over

dbSNP: rs41321052; hg19: chr16-223477; API