rs33935673

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 6P and 1B. PM1PM2PP3_ModerateBP6

The NM_000518.5(HBB):​c.353A>G​(p.His118Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,922 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). Synonymous variant affecting the same amino acid position (i.e. H118H) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

HBB
NM_000518.5 missense

Scores

4
6
9

Clinical Significance

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

Conservation

PhyloP100: 2.20

Publications

3 publications found
Variant links:
Genes affected
HBB (HGNC:4827): (hemoglobin subunit beta) The alpha (HBA) and beta (HBB) loci determine the structure of the 2 types of polypeptide chains in adult hemoglobin, Hb A. The normal adult hemoglobin tetramer consists of two alpha chains and two beta chains. Mutant beta globin causes sickle cell anemia. Absence of beta chain causes beta-zero-thalassemia. Reduced amounts of detectable beta globin causes beta-plus-thalassemia. The order of the genes in the beta-globin cluster is 5'-epsilon -- gamma-G -- gamma-A -- delta -- beta--3'. [provided by RefSeq, Jul 2008]
HBB Gene-Disease associations (from GenCC):
  • dominant beta-thalassemia
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen
  • hemoglobin M disease
    Inheritance: AD Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, ClinGen
  • beta thalassemia
    Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
  • beta-thalassemia HBB/LCRB
    Inheritance: AR, SD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
  • sickle cell disease and related diseases
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • erythrocytosis, familial, 6
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • Heinz body anemia
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • sickle cell disease
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
  • hereditary persistence of fetal hemoglobin-beta-thalassemia syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • beta-thalassemia intermedia
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • beta-thalassemia major
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • delta-beta-thalassemia
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hemoglobin C disease
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hemoglobin C-beta-thalassemia syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hemoglobin E disease
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hemoglobin E-beta-thalassemia syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hereditary persistence of fetal hemoglobin-sickle cell disease syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • sickle cell-beta-thalassemia disease syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • sickle cell-hemoglobin c disease syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • sickle cell-hemoglobin d disease syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • sickle cell-hemoglobin E disease syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM1
In a hotspot region, there are 14 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 28 uncertain in NM_000518.5
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.863
BP6
Variant 11-5225689-T-C is Benign according to our data. Variant chr11-5225689-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 36324.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HBBNM_000518.5 linkc.353A>G p.His118Arg missense_variant Exon 3 of 3 ENST00000335295.4 NP_000509.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HBBENST00000335295.4 linkc.353A>G p.His118Arg missense_variant Exon 3 of 3 1 NM_000518.5 ENSP00000333994.3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152112
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000242
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
AF:
6.84e-7
AC:
1
AN:
1461810
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727218
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39690
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111948
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.275
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
AF:
0.00000657
AC:
1
AN:
152112
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74306
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41402
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10598
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0

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
Aug 14, 2017
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 21, 2023
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The HBB c.353A>G (p.His118Arg) variant has been reported in the published literature in heterozygous individuals or compound heterozygous with Hb C, as having normal to minimal clinical presentations (PMIDs: 1164567 (1975), 700140 (1978), and 6859036 (1983)). Additionally, it is reported as having normal stability and a minimally increased oxygen affinity. The frequency of this variant in the general population, 0.0000066 (1/152112 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. 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. -

not specified Uncertain:1
Nov 08, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: HBB c.353A>G (p.His118Arg) results in a non-conservative amino acid change located in the Globin domain (IPR000971) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 251276 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.353A>G has been reported in multiple individuals heterozygously and in compound heterozygosity with HbC or HbS and beta-thal variants. Compound hets patients showed minimal to no clinical features and hematological values were compared to b-thal, HbC or HbS carriers (Di Iorio_HBB_Blut_1975, Huisman_HBB_Febbs Lett_1978). At least one functional study showed that HbP does not differ significantly from WT (Hb A) with regard to oxygen affinity or stability (Di Iorio_HBB_Blut_1975). The following publications have been ascertained in the context of this evaluation (PMID: 20395516, 1164567, 6859036, 700140, 10870891, 11694258, 12386379, 14109943, 8330975). ClinVar contains an entry for this variant (Variation ID: 36324). Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Pathogenic
0.39
D
BayesDel_noAF
Pathogenic
0.33
CADD
Benign
18
DANN
Benign
0.89
DEOGEN2
Benign
0.14
T;T
Eigen
Benign
-0.45
Eigen_PC
Benign
-0.45
FATHMM_MKL
Uncertain
0.86
D
LIST_S2
Benign
0.57
.;T
M_CAP
Uncertain
0.19
D
MetaRNN
Pathogenic
0.86
D;D
MetaSVM
Uncertain
0.071
D
MutationAssessor
Uncertain
2.3
M;M
PhyloP100
2.2
PrimateAI
Benign
0.38
T
PROVEAN
Pathogenic
-4.4
D;.
REVEL
Uncertain
0.56
Sift
Uncertain
0.026
D;.
Sift4G
Benign
0.12
T;.
Polyphen
0.0050
B;B
Vest4
0.43
MutPred
0.74
Loss of ubiquitination at K121 (P = 0.0716);Loss of ubiquitination at K121 (P = 0.0716);
MVP
0.95
MPC
0.039
ClinPred
0.18
T
GERP RS
3.5
Varity_R
0.47
gMVP
0.83
Mutation Taster
=9/91
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: rs33935673; hg19: chr11-5246919; API