Genetic Variant HBB:c.92+5G>T (chr11-5226925-C-A) – ACMG Classification: Pathogenic (14 pts)

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 region, 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. 3/3 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_region, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:10

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]

HBB links:

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, max_spliceai. 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 rank	MANE	Protein	UniProt
HBB	NM_000518.5 link	c.92+5G>T		splice_region_variant, intron_variant	Intron 1 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.92+5G>T		splice_region_variant, intron_variant	Intron 1 of 2	1	NM_000518.5	ENSP00000333994.3		P68871

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251204

Hom.:

AF XY:

0.00

AC XY:

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:

AN:

1459918

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

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.:

Bravo

AF:

0.00000378

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:4

Dec 06, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This 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. -

Jul 22, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The 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. -

Sep 07, 2016

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jun 26, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Intronic +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) -

beta Thalassemia

Pathogenic:3

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

- -

Mar 17, 2017

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Sep 03, 2015

Counsyl

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Beta-thalassemia major

Pathogenic:1

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

- -

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

May 10, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Beta-plus-thalassemia

Pathogenic:1

Mar 01, 1989

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

-0.39

CADD

Benign

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.

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