chr11-5226928-A-G
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000518.5(HBB):c.92+2T>C variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,106 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).
Frequency
Consequence
NM_000518.5 splice_donor, intron
Scores
Clinical Significance
Conservation
Publications
- dominant beta-thalassemiaInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen
- hemoglobin M diseaseInheritance: AD Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, ClinGen
- beta thalassemiaInheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
- beta-thalassemia HBB/LCRBInheritance: AR, SD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
- sickle cell disease and related diseasesInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- erythrocytosis, familial, 6Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
- Heinz body anemiaInheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- sickle cell diseaseInheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
- hereditary persistence of fetal hemoglobin-beta-thalassemia syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- beta-thalassemia intermediaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- beta-thalassemia majorInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- delta-beta-thalassemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hemoglobin C diseaseInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hemoglobin C-beta-thalassemia syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hemoglobin E diseaseInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hemoglobin E-beta-thalassemia syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hereditary persistence of fetal hemoglobin-sickle cell disease syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- sickle cell-beta-thalassemia disease syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- sickle cell-hemoglobin c disease syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- sickle cell-hemoglobin d disease syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- sickle cell-hemoglobin E disease syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 18 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152106Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000159 AC: 4AN: 251218 AF XY: 0.0000221 show subpopulations
GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000274 AC: 4AN: 1460306Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2AN XY: 726588 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152106Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74290 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
beta Thalassemia Pathogenic:3
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Variant summary: HBB c.92+2T>C is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. The variant allele was found at a frequency of 1.6e-05 in 251218 control chromosomes. c.92+2T>C has been reported in the literature in multiple individuals affected with Beta Thalassemia (Gonzalez-Redondo_1989, Bouhass_1990, Agouti_2008, IbnAyub_2010). These data indicate that the variant is very likely to be associated with disease. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
not provided Pathogenic:3
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. ClinVar contains an entry for this variant (Variation ID: 36334). Disruption of this splice site has been observed in individuals with beta thalassemia (PMID: 2200760, 24986053, 28366028, 28391758). This variant is present in population databases (rs33956879, gnomAD 0.004%). This sequence change affects a donor splice site in intron 1 of the HBB gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in HBB are known to be pathogenic (PMID: 23637309). -
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The HBB c.92+2T>C variant (rs33956879, HbVar ID: 820), also known as IVS-I-2 (T>C), has been reported in an individual with HbS/beta(0) thalassemia (Gonzalez-Redondo 1989), and an individual with beta-thalassemia major (Kluge 2014). It was found in-trans with another pathogenic variant in both reported cases (Gonzalez-Redondo 1989, Kluge 2014). The c.92+2T>C variant is reported as pathogenic in ClinVar (Variation ID: 36334), and found in the general population with a low overall allele frequency of 0.002% (4/245978 alleles) in the Genome Aggregation Database. This variant abolishes the canonical splice donor site of intron 1, which is likely to disrupt gene function. Based on available information, this variant is considered to be pathogenic. References: Link to HbVar database: https://globin.bx.psu.edu/hbvar/hbvar.html Gonzalez-Redondo J et al. Severe Hb S-beta zero-thalassaemia with a T----C substitution in the donor splice site of the first intron of the beta-globin gene. Br J Haematol. 1989; 71(1):113-7. PMID: 2917118 Kluge M et al. Beta-Thalassemia major resulting from compound heterozygosity for HBB: c.92+2T>C [formerly known as IVS-I-2 (T>C)] and a novel beta(0)-thalassemia frameshift mutation: HBB: c.209delG; p.Gly70Valfs*20. Hemoglobin. 2014; 38(4):292-4. PMID: 24986053 -
Beta zero thalassemia Pathogenic:1
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alpha Thalassemia;C0002895: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
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at