rs878854574

Variant summary

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

The NM_003000.3(SDHB):​c.201-2A>C variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000124 in 1,607,858 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

SDHB
NM_003000.3 splice_acceptor, intron

Scores

5
1
1
Splicing: ADA: 1.000
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:2

Conservation

PhyloP100: 7.03
Variant links:
Genes affected
SDHB (HGNC:10681): (succinate dehydrogenase complex iron sulfur subunit B) This tumor suppressor gene encodes the iron-sulfur protein subunit of the succinate dehydrogenase (SDH) enzyme complex which plays a critical role in mitochondria. The SDH enzyme complex is composed of four nuclear-encoded subunits. This enzyme complex converts succinate to fumarate which releases electrons as part of the citric acid cycle, and the enzyme complex additionally provides an attachment site for released electrons to be transferred to the oxidative phosphorylation pathway. The SDH enzyme complex plays a role in oxygen-related gene regulation through its conversion of succinate, which is an oxygen sensor that stabilizes the hypoxia-inducible factor 1 (HIF1) transcription factor. Sporadic and familial mutations in this gene result in paragangliomas, pheochromocytoma, and gastrointestinal stromal tumors, supporting a link between mitochondrial dysfunction and tumorigenesis. Mutations in this gene are also implicated in nuclear type 4 mitochondrial complex II deficiency. [provided by RefSeq, Jun 2022]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-17033147-T-G is Pathogenic according to our data. Variant chr1-17033147-T-G is described in ClinVar as [Pathogenic]. Clinvar id is 239425.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SDHBNM_003000.3 linkc.201-2A>C splice_acceptor_variant, intron_variant Intron 2 of 7 ENST00000375499.8 NP_002991.2 P21912
SDHBNM_001407361.1 linkc.201-2A>C splice_acceptor_variant, intron_variant Intron 2 of 7 NP_001394290.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SDHBENST00000375499.8 linkc.201-2A>C splice_acceptor_variant, intron_variant Intron 2 of 7 1 NM_003000.3 ENSP00000364649.3 P21912

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152200
Hom.:
0
Cov.:
33
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:
0.000192
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
GnomAD4 exome
AF:
6.87e-7
AC:
1
AN:
1455658
Hom.:
0
Cov.:
28
AF XY:
0.00
AC XY:
0
AN XY:
724574
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152200
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74356
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.000192
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Pheochromocytoma;C0238198:Gastrointestinal stromal tumor;C1861848:Paragangliomas 4 Pathogenic:1
Aug 26, 2020
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Donor and acceptor splice site variants typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in SDHB are known to be pathogenic (PMID: 19454582, 19802898). This variant has been observed in individual(s) with SDHB-related conditions (PMID: 28960644, 29925701). ClinVar contains an entry for this variant (Variation ID: 239425). This variant is not present in population databases (ExAC no frequency). This sequence change affects an acceptor splice site in intron 2 of the SDHB gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. -

Hereditary cancer-predisposing syndrome Pathogenic:1
Feb 24, 2023
Ambry Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The c.201-2A>C intronic pathogenic mutation results from an A to C substitution two nucleotides upstream from coding exon 3 in the SDHB gene. This alteration has been observed in at least one individual with a personal and/or family history that is consistent with SDHB-related disease (Ambry internal data; Iwashita H et al. Pathol Int, 2017 Nov;67:585-589; Yamanaka M et al. Tohoku J Exp Med, 2018 Jun;245:99-105). Of note, this alteration is also designated as IVS2-2A>C in published literature. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.25
CADD
Pathogenic
27
DANN
Uncertain
0.99
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.85
FATHMM_MKL
Pathogenic
0.99
D
GERP RS
5.4

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.93
SpliceAI score (max)
0.97
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.97
Position offset: -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: rs878854574; hg19: chr1-17359642; API