dbSNP rs33931746: HBB:c.-78A>G (chr11-5227099-T-C) – ACMG Classification: Likely_pathogenic (9 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 10P and 1B. PM2PP5_Very_StrongBP4

The ENST00000647020.1(HBB):c.-78A>G variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000256 in 1,017,432 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

HBB
ENST00000647020.1 5_prime_UTR

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:11O:1

Conservation

PhyloP100: 1.34

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 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 11-5227099-T-C is Pathogenic according to our data. Variant chr11-5227099-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 15471.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-5227099-T-C is described in Lovd as [Pathogenic].

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.25). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HBB	NM_000518.5 link	c.-78A>G		upstream_gene_variant		ENST00000335295.4	NP_000509.1	P68871D9YZU5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HBB	ENST00000335295.4 link	c.-78A>G		upstream_gene_variant		1	NM_000518.5	ENSP00000333994.3		P68871

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152146

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

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:

0.0000289

AC:

AN:

865286

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

453722

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000648

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000245

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152146

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74326

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000151

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:11Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

beta Thalassemia

Pathogenic:4Other:1

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

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

- -

Dec 09, 2019

Myriad Genetics, Inc.

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

NM_000518.4(HBB):c.-78A>G(aka -28A>G) is classified as likely pathogenic in the context of Hb beta chain-related hemoglobinopathy and is a beta-plus variant associated with beta thalessemia. Sources cited for classification include the following: PMID 8435318, 9160698 and 6308558. Classification of NM_000518.4(HBB):c.-78A>G(aka -28A>G) is based on the following criteria: This variant has been observed more frequently in patients with clinical diagnoses than in healthy populations. Please note: this variant was assessed in the context of healthy population screening. -

Mar 17, 2017

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Aug 18, 2011

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing;curation

- -

not provided

Pathogenic:3

Sep 04, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The HBB c.-78A>G variant (also known as -28A>G, rs33931746, HbVar ID: 769) is a common beta+ thalassemia variant found in Asian populations (see HbVar link, Yamsri 2011), and has been reported in an individual with beta thalassemia who was homozygous for the variant (Orkin 1983). In addition, functional characterization of the variant indicates a 3-5 fold reduction of beta globin mRNA (Orkin 1983). This variant is absent from the Genome Aggregation Database, indicating it is not a common polymorphism. The c.-78A>G variant is located in a conserved region of the beta globin gene promoter and is considered to be pathogenic. References: Link to HbVar database: https://globin.bx.psu.edu/hbvar/hbvar.html Orkin SH et al. ATA box transcription mutation in beta-thalassemia. Nucleic Acids Res. 1983 Jul 25;11(14):4727-34. PMID: 6308558. Yamsri S et al. Genotype and phenotype characterizations in a large cohort of beta-thalassemia heterozygote with different forms of alpha-thalassemia in northeast Thailand. Blood Cells Mol Dis. 2011 Aug 15;47(2):120-4. PMID: 21664157. -

Apr 20, 2017

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 13, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant occurs in a non-coding region of the HBB gene. It does not change the encoded amino acid sequence of the HBB protein. This variant is present in population databases (rs33931746, gnomAD 0.06%). This variant has been observed in individual(s) with autosomal recessive beta thalassemia (PMID: 2014803, 8435318, 20035706, 28385923). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is also known as -28A>G. ClinVar contains an entry for this variant (Variation ID: 15471). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this variant affects HBB function (PMID: 6308558). For these reasons, this variant has been classified as Pathogenic. -

Beta-thalassemia HBB/LCRB

Pathogenic:1

Juno Genomics, Hangzhou Juno Genomics, Inc

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_Supporting+PM3_VeryStrong+PS3_Moderate+PP4 -

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

Mar 26, 2024

Fulgent Genetics, Fulgent Genetics

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

- -

Beta-plus-thalassemia

Pathogenic:1

Jul 25, 1983

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.25

CADD

Benign

DANN

Benign

0.87

Splicing

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over