rs35497102

Variant summary

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

The NM_000518.5(HBB):​c.25_26del​(p.Lys9ValfsTer14) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000958 in 1,460,874 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

HBB
NM_000518.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:19O:1

Conservation

PhyloP100: 4.20
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]

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 159 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 11-5226995-CTT-C is Pathogenic according to our data. Variant chr11-5226995-CTT-C is described in ClinVar as [Pathogenic]. Clinvar id is 15413.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-5226995-CTT-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
HBBNM_000518.5 linkuse as main transcriptc.25_26del p.Lys9ValfsTer14 frameshift_variant 1/3 ENST00000335295.4 NP_000509.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
HBBENST00000335295.4 linkuse as main transcriptc.25_26del p.Lys9ValfsTer14 frameshift_variant 1/31 NM_000518.5 ENSP00000333994 P1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152200
Hom.:
0
Cov.:
32
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:
0.00
Gnomad SAS
AF:
0.000208
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000797
AC:
2
AN:
251086
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135676
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:
0.0000328
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000881
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000958
AC:
14
AN:
1460874
Hom.:
0
AF XY:
0.0000138
AC XY:
10
AN XY:
726840
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:
0.0000348
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000450
Gnomad4 OTH exome
AF:
0.0000828
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.000111
Hom.:
0

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:19Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:8
Pathogenic, criteria provided, single submitterclinical testingQuest Diagnostics Nichols Institute San Juan CapistranoNov 12, 2016- -
Pathogenic, criteria provided, single submitterclinical testingInstitute of Medical Genetics and Applied Genomics, University Hospital TübingenOct 23, 2020- -
Pathogenic, criteria provided, single submitterclinical testingAl Jalila Children’s Genomics Center, Al Jalila Childrens Speciality HospitalDec 17, 2022- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 15, 2024This sequence change creates a premature translational stop signal (p.Lys9Valfs*14) 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 (rs35497102, gnomAD 0.007%). This premature translational stop signal has been observed in individuals with HBB-related conditions (PMID: 3828533, 25405919, 26771086, 28391758). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 15413). 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. -
Pathogenic, criteria provided, single submitterclinical testingClinical Genetics and Genomics, Karolinska University HospitalMar 08, 2016- -
Pathogenic, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenDec 01, 2023HBB: PVS1, PS4:Moderate -
Pathogenic, criteria provided, single submitterclinical testingCenter for Genomic Medicine, Rigshospitalet, Copenhagen University HospitalJul 31, 2024- -
Pathogenic, criteria provided, single submitterclinical testingARUP Laboratories, Molecular Genetics and Genomics, ARUP LaboratoriesOct 25, 2023The HBB c.25_26del; p.Lys9ValfsTer14 variant (also known as Lys8fsTer14 when numbered from the mature protein or as Codon 8 (-AA), rs35497102, Hbvar ID: 785) has been reported in multiple patients with beta (0) thalassemia, both in the homozygous state and in trans to another pathogenic variant (Jalilian 2017, Orkin 1981, HbVar database and references therein). This variant is found on only two chromosomes in the Genome Aggregation Database, indicating it is not a common polymorphism. This variant causes a frameshift by deleting two nucleotides, 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 database: https://globin.bx.psu.edu/hbvar/hbvar.html Jalilian M et al. The Frequency of HBB Mutations Among beta-Thalassemia Patients in Hamadan Province, Iran. Hemoglobin. 2017 Jan;41(1):61-64. PMID: 28391758. Orkin S et al. Nonsense and frameshift mutations in beta 0-thalassemia detected in cloned beta-globin genes. J Biol Chem. 1981; 256(19):9782-4. PMID: 6985481. -
beta Thalassemia Pathogenic:4Other:1
Pathogenic, no assertion criteria providedclinical testingNatera, Inc.Mar 17, 2017- -
Pathogenic, criteria provided, single submitterclinical testing;curationWomen's Health and Genetics/Laboratory Corporation of America, LabCorpAug 18, 2011- -
Pathogenic, no assertion criteria providedcurationThe ITHANET community portal, The Cyprus Institute of Neurology and GeneticsNov 25, 2019- -
not provided, no classification providedliterature onlyGeneReviews-- -
Pathogenic, criteria provided, single submitterclinical testingMyriad Genetics, Inc.Dec 20, 2019NM_000518.4(HBB):c.25_26delAA(aka K9Vfs*14) 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 22851993, 25155404, 23321370, 2200760, 6985481 and 22110956. Classification of NM_000518.4(HBB):c.25_26delAA(aka K9Vfs*14) 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. -
Beta-thalassemia HBB/LCRB Pathogenic:3
Pathogenic, criteria provided, single submitterclinical testing3billionFeb 23, 2023The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: <0.001%). This variant was predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000015413 / PMID: 3828533). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -
Pathogenic, no assertion criteria providedclinical testingZotz-Klimas Genetics Lab, MVZ Zotz KlimasOct 09, 2023- -
Pathogenic, criteria provided, single submitterclinical testingMGZ Medical Genetics CenterApr 27, 2022- -
Beta zero thalassemia Pathogenic:1
Pathogenic, no assertion criteria providedliterature onlyOMIMApr 01, 1995- -
HBB-related disorder Pathogenic:1
Pathogenic, no assertion criteria providedclinical testingPreventionGenetics, part of Exact SciencesMay 10, 2024The HBB c.25_26delAA variant is predicted to result in a frameshift and premature protein termination (p.Lys9Valfs*14). This variant has been reported along with a second HBB variant many times in individuals with beta thalassemia (see for examples, Figure 2 in Orkin et al. 1981. PubMed ID: 6985481; Diaz-Chico et al. 1988. PubMed ID: 2446680; Shammas et al. 2010. PubMed ID: 20704537 Jalilian et al. 2017. PubMed ID: 28391758). This variant is reported in 0.0033% of alleles in individuals of South Asian descent in gnomAD. Frameshift variants in HBB are expected to be pathogenic. This variant is interpreted as pathogenic. -
Malaria, susceptibility to Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingCenter for Genomic Medicine, King Faisal Specialist Hospital and Research CenterMar 29, 2024- -
Hb SS disease Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingBaylor Genetics-- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs35497102; hg19: chr11-5248225; API