rs33914668

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000518.5(HBB):c.316-2A>G variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.000013 in 1,613,914 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

HBB
NM_000518.5 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:12O:1

Conservation

PhyloP100: 5.51

Publications

9 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

HBB links:

ENSG00000298932 (HGNC:):

ENSG00000298932 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease,

PP5

Variant 11-5225728-T-C is Pathogenic according to our data. Variant chr11-5225728-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 21191.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HBB	NM_000518.5 link	c.316-2A>G		splice_acceptor_variant, intron_variant	Intron 2 of 2	ENST00000335295.4	NP_000509.1	P68871D9YZU5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HBB	ENST00000335295.4 link	c.316-2A>G		splice_acceptor_variant, intron_variant	Intron 2 of 2	1	NM_000518.5	ENSP00000333994.3		P68871

Frequencies

GnomAD3 genomes

AF:

0.0000395

AC:

AN:

152090

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000145

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

GnomAD2 exomes

AF:

0.00000797

AC:

AN:

251048

AF XY:

0.00000737

show subpopulations

Gnomad AFR exome

AF:

0.000123

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:

0.0000103

AC:

AN:

1461706

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

727164

show subpopulations

African (AFR)

AF:

0.000418

AC:

AN:

33476

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39694

South Asian (SAS)

AF:

0.00

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53408

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111864

Other (OTH)

AF:

0.0000166

AC:

AN:

60384

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.478

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000394

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.0000806

AC XY:

AN XY:

74404

show subpopulations

African (AFR)

AF:

0.000145

AC:

AN:

41514

American (AMR)

AF:

0.00

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4818

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68004

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.467

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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.:

Bravo

AF:

0.000102

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:12Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

beta Thalassemia

Pathogenic:4Other:1

Nov 25, 2019

The ITHANET community portal, The Cyprus Institute of Neurology and Genetics

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:curation

- -

GeneReviews

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

- -

Mar 17, 2017

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Dec 09, 2019

Myriad Genetics, Inc.

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

NM_000518.4(HBB):c.316-2A>G is classified as pathogenic in the context of Hb beta chain-related hemoglobinopathy; it is associated with beta thalassemia and is classified as a beta-zero variant. Sources cited for classification include the following: PMID 21250876, 2987809 and 2123063. Classification of NM_000518.4(HBB):c.316-2A>G is based on the following criteria: The variant is located at a canonical splice site, is expected to disrupt gene function and is reported in individuals with the relevant phenotype. Please note: this variant was assessed in the context of healthy population screening. -

Sep 18, 2018

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: HBB c.316-2A>G is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Five predict the variant abolishes a 3 acceptor site. Two publications report experimental evidence that this variant affects mRNA splicing (Antonarakis_1984, Atweh_1985). The variant allele was found at a frequency of 1.1e-05 in 276762 control chromosomes (gnomAD). The variant, c.316-2A>G, has been reported in the literature in multiple individuals affected with Beta Thalassemia (Bravo-Urquiola_2012, Codrington_1990, Antonarakis_1984, Atweh_1985, Huisman_1997). These data indicate that the variant is very likely to be associated with disease. Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided

Pathogenic:4

Jun 30, 2017

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 23, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The HBB c.316-2A>G variant (also known as IVS-II-849 (A->G), rs33914668, Hbvar ID: 940) is reported in the literature in both homozygous and compound heterozygous individuals affected with beta(0) thalassemia (Antonarakis 1984, Atweh 1985, HbVar database and references therein). This variant is found on only three chromosomes (3/282432 alleles) in the Genome Aggregation Database, indicating it is not a common polymorphism. This variant abolishes the canonical splice acceptor site of intron 2, which is likely to disrupt gene function. Indeed, RNA analyses of patient cells carrying the c.316-2A>G variant suggest altered splicing and retention of sections of intron 3 in the mature mRNA (Antonarakis 1984, Atweh 1985). Based on available information, this variant is considered to be pathogenic. References: Link to HbVar database: https://globin.bx.psu.edu/hbvar/hbvar.html Antonarakis S et al. beta-Thalassemia in American Blacks: novel mutations in the "TATA" box and an acceptor splice site. Proc Natl Acad Sci U S A. 1984; 81(4):1154-8. PMID: 6583702 Atweh G et al. Beta-thalassemia resulting from a single nucleotide substitution in an acceptor splice site. Nucleic Acids Res. 1985; 13(3):777-90. PMID: 2987809 -

May 02, 2024

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Canonical splice site variant expected to result in aberrant splicing, and published functional studies show this variant causes the production of an alternatively splice transcript which is not able to encode normal beta-globin (PMID: 6583702); This variant is associated with the following publications: (PMID: 21250876, 22563936, 22975760, 9342003, 32172616, 6583702, 1427786, 2123063, 2987809, 30626236, 23348723, 27251090, 26583619, 38293657, 37496383, 33935034, 38007159, 36106931) -

Dec 18, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change affects an acceptor splice site in intron 2 of the HBB gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in the gain of 90 amino acid residue(s), but is expected to preserve the integrity of the reading-frame. This variant is present in population databases (rs33914668, gnomAD 0.01%). Disruption of this splice site has been observed in individuals with autosomal recessive beta-thalassemia (PMID: 2123063, 6583702). It has also been observed to segregate with disease in related individuals. This variant is also known as IVSII-849A>G. ClinVar contains an entry for this variant (Variation ID: 21191). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that disruption of this splice site results in the activation of a cryptic splice site in intron 2 (PMID: 6583702). For these reasons, this variant has been classified as Pathogenic. -

Beta zero thalassemia

Pathogenic:1

Sep 01, 1992

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

alpha Thalassemia;C0002895:Hb SS disease;C0019025:Hereditary persistence of fetal hemoglobin;C0700299:Heinz body anemia;C1840779:METHEMOGLOBINEMIA, BETA TYPE;C1858990:Dominant beta-thalassemia;C1970028:Malaria, susceptibility to;C4693822:Erythrocytosis, familial, 6;CN322236:Beta-thalassemia HBB/LCRB

Pathogenic:1

Feb 25, 2022

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Hb SS disease;C0019025:Hereditary persistence of fetal hemoglobin;C0700299:Heinz body anemia;C1840779:METHEMOGLOBINEMIA, BETA TYPE;C1858990:Dominant beta-thalassemia;C1970028:Malaria, susceptibility to;C4693822:Erythrocytosis, familial, 6;CN322236:Beta-thalassemia HBB/LCRB

Pathogenic:1

Nov 07, 2023

Molecular Genetics and NGS Laboratory, Hospital Fundacion Valle Del Lili

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Hb SS disease

Pathogenic:1

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.44

BayesDel_noAF

Pathogenic

0.25

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.82

FATHMM_MKL

Uncertain

0.96

PhyloP100

5.5

GERP RS

4.7

Mutation Taster

=1/99

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.98

Position offset: -2

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over