rs33986703

Positions:

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000518.5(HBB):c.52A>T(p.Lys18Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000118 in 1,614,014 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. K18K) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

HBB
NM_000518.5 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:15O:1

Conservation

PhyloP100: 5.56

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 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. There are 333 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 11-5226970-T-A is Pathogenic according to our data. Variant chr11-5226970-T-A is described in ClinVar as [Pathogenic]. Clinvar id is 15401.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-5226970-T-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HBB	NM_000518.5 linkuse as main transcript	c.52A>T	p.Lys18Ter	stop_gained	1/3	ENST00000335295.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HBB	ENST00000335295.4 linkuse as main transcript	c.52A>T	p.Lys18Ter	stop_gained	1/3	1	NM_000518.5	P1

Frequencies

GnomAD3 genomes

AF:

0.0000591

AC:

AN:

152212

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:

0.00173

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

GnomAD3 exomes

AF:

0.0000557

AC:

AN:

251268

Hom.:

AF XY:

0.0000589

AC XY:

AN XY:

135792

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000762

Gnomad SAS 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:

0.00000684

AC:

AN:

1461684

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727164

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000227

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000591

AC:

AN:

152330

Hom.:

Cov.:

AF XY:

0.000107

AC XY:

AN XY:

74502

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00174

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000427

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:15Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:6

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 28, 2022	Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 21389146, 88735, 26029792, 30275481, 34426522, 8161731, 2143120, 26715484, 22975760, 29669226, 29695942) -
Pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Nov 16, 2023	The HBB c.52A>T; p.Lys18Ter variant (also known as Lys17Ter when numbered from the mature protein or as Codon 17 (A>T), rs33986703, HbVar ID: 800) has been reported in multiple individuals with beta thalassemia, and is considered a beta(0) thalassemia variant (HbVar database and references therein). This variant introduces a premature termination codon, so it is predicted to result in a truncated protein or mRNA subject to nonsense-mediated decay. Based on available information, this variant is considered to be pathogenic. References: Link to HbVar: https://globin.bx.psu.edu/hbvar/hbvar.html -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Genetics and Genomics, Karolinska University Hospital	Jul 13, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Dec 01, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Aug 30, 2021	The nonsense variant causes the premature termination of HBB protein synthesis. In addition, it has been reported to be associated with beta(0)-thalassemia in the published literature (PMID: 29695942 (2018), 9101288 (1997), 2606476 (1989) and 88735 (1979)). Based on the available information, this variant is classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 17, 2024	This sequence change creates a premature translational stop signal (p.Lys18*) in the HBB gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in HBB are known to be pathogenic (PMID: 23637309). This variant is present in population databases (rs33986703, gnomAD 0.06%). This premature translational stop signal has been observed in individuals with beta thalassemia (PMID: 88735, 24857915, 26029792). It is commonly reported in individuals of Asian ancestry (PMID: 20412082, 25089872, 25849334, 29695942). This variant is also known as "Codon 17 (A->T)" and "AAG(Lys)->TAG(stop codon) beta0". ClinVar contains an entry for this variant (Variation ID: 15401). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

beta Thalassemia

Pathogenic:5Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jul 28, 2016	Variant summary: The HBB c.52A>T (p.Lys18X) variant results in a premature termination codon, predicted to cause a truncated or absent HBB protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory (e.g.c.85dupC/p.Leu29fsX16). One in silico tool predicts a damaging outcome for this variant. This variant was found in 2/121842 control chromosomes at a frequency of 0.0000164, which does not exceed the estimated maximal expected allele frequency of a pathogenic HBB variant (0.0111803). This variant has been reported in many BTHAL patients (mostly East Asian) both homozygously and in compound heterozygosity with other pathogenic variant. In addition, multiple reputable databases classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -
Pathogenic, no assertion criteria provided	curation	The ITHANET community portal, The Cyprus Institute of Neurology and Genetics	Nov 25, 2019	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 17, 2017	- -
not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Dec 19, 2019	NM_000518.4(HBB):c.52A>T(K18) 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 22335963. Classification of NM_000518.4(HBB):c.52A>T(K18) is based on the following criteria: The variant causes a premature termination codon that is expected to be targeted by nonsense-mediated mRNA decay and is reported in individuals with the relevant phenotype. Please note: this variant was assessed in the context of healthy population screening. -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jul 24, 2020	This variant was determined to be pathogenic according to ACMG Guidelines, 2015 [PMID:25741868]. -

Beta zero thalassemia

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jan 01, 2000

- -

Beta-thalassemia HBB/LCRB

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

MGZ Medical Genetics Center

Mar 15, 2022

- -

alpha Thalassemia;C0002895:Hb SS disease;C0005283:beta Thalassemia;C0700299:Heinz body anemia;C1840779:METHEMOGLOBINEMIA, BETA TYPE;C1841621:Fetal hemoglobin quantitative trait locus 1;C1858990:Dominant beta-thalassemia;C1970028:Malaria, susceptibility to;C4693822:Erythrocytosis, familial, 6

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Hb SS disease

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.37

BayesDel_noAF

Pathogenic

0.62

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.80

Eigen_PC

Uncertain

0.65

FATHMM_MKL

Pathogenic

0.98

MutationTaster

Benign

1.0

Vest4

0.71

GERP RS

5.2

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

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.

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