Menu
GeneBe

rs33915217

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_000518.5(HBB):c.92+5G>T variant causes a splice donor 5th base, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,459,918 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/2 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

HBB
NM_000518.5 splice_donor_5th_base, intron

Scores

2
Splicing: ADA: 1.000
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 2.72
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 14 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
Variant 11-5226925-C-A is Pathogenic according to our data. Variant chr11-5226925-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 15448.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-5226925-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
HBBNM_000518.5 linkuse as main transcriptc.92+5G>T splice_donor_5th_base_variant, intron_variant ENST00000335295.4

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
HBBENST00000335295.4 linkuse as main transcriptc.92+5G>T splice_donor_5th_base_variant, intron_variant 1 NM_000518.5 P1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251204
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
135754
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:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000881
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1459918
Hom.:
0
Cov.:
33
AF XY:
0.00000138
AC XY:
1
AN XY:
726420
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
9.01e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
Bravo
AF:
0.00000378
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:9
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:4
Pathogenic, criteria provided, single submitterclinical testingQuest Diagnostics Nichols Institute San Juan CapistranoSep 07, 2016- -
Pathogenic, criteria provided, single submitterclinical testingGeneDxJun 26, 2023Intronic +5 splice site variant in a gene for which loss of function is a known mechanism of disease, and splice predictors support a deleterious effect; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 23348723, 22975760, 25525159, 9163586, 2577233, 2439149, 33092414) -
Pathogenic, criteria provided, single submitterclinical testingInvitaeDec 06, 2023This sequence change falls in intron 1 of the HBB gene. It does not directly change the encoded amino acid sequence of the HBB protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or disrupted protein product. This variant is present in population databases (rs33915217, gnomAD 0.0009%). This variant has been observed in individuals with beta-thalassemia (PMID: 2439149). ClinVar contains an entry for this variant (Variation ID: 15448). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in alternate splicing and introduces a premature termination codon (PMID: 2439149). The resulting mRNA is expected to undergo nonsense-mediated decay. This variant disrupts the c.92+5G nucleotide in the HBB gene. Other variant(s) that disrupt this nucleotide have been determined to be pathogenic (PMID: 2200760, 3021139, 23162295, 27263053). This suggests that this nucleotide is clinically significant, and that variants that disrupt this position are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingARUP Laboratories, Molecular Genetics and Genomics, ARUP LaboratoriesApr 17, 2023The HBB c.92+5G>T variant (rs33915217, HbVar ID: 825), also known as IVS-I-5 (G->T), has been reported in the homozygous or compound heterozygous state in several individuals affected with beta(+) thalassemia (Atweh 1987, HbVar database and references therein). Functional studies indicate that the variant causes aberrant splicing of the HBB transcript and reduction of full-length mRNA (Atweh 1987). The variant is listed as pathogenic in ClinVar (Variation ID: 15448), and observed once in the Genome Aggregation Database (1/251204 alleles). Consistent with functional studies, computational analyses (Alamut v.2.11) predict that this variant impacts splicing by weakening the nearby canonical donor splice site. Based on available information, the variant c.92+5G>T is classified as pathogenic. References: Link to HbVar database: https://globin.bx.psu.edu/hbvar/hbvar.html Atweh G et al. A new mutation in IVS-1 of the human beta globin gene causing beta thalassemia due to abnormal splicing. Blood. 1987; 70(1):147-51. PMID: 2439149. -
beta Thalassemia Pathogenic:3
Pathogenic, no assertion criteria providedclinical testingCounsylSep 03, 2015- -
Pathogenic, no assertion criteria providedclinical testingNatera, Inc.Mar 17, 2017- -
Pathogenic, no assertion criteria providedcurationThe ITHANET community portal, The Cyprus Institute of Neurology and GeneticsNov 25, 2019- -
Beta-thalassemia major Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testing;curationWomen's Health and Genetics/Laboratory Corporation of America, LabCorpAug 18, 2011- -
Beta-plus-thalassemia Pathogenic:1
Pathogenic, no assertion criteria providedliterature onlyOMIMMar 01, 1989- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.39
Cadd
Benign
20
Dann
Benign
0.73

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.99
SpliceAI score (max)
0.73
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.47
Position offset: 21
DS_DL_spliceai
0.73
Position offset: 5

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: rs33915217; hg19: chr11-5248155; API