rs553392349

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP3

The NM_003000.3(SDHB):​c.398T>C​(p.Met133Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,614,194 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M133I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

SDHB
NM_003000.3 missense

Scores

10
5
4

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 8.56

Publications

0 publications found
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]
SDHB Gene-Disease associations (from GenCC):
  • Carney-Stratakis syndrome
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet
  • gastrointestinal stromal tumor
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae)
  • hereditary pheochromocytoma-paraganglioma
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
  • pheochromocytoma
    Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
  • pheochromocytoma/paraganglioma syndrome 4
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • mitochondrial disease
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • renal cell carcinoma
    Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
  • mitochondrial complex 2 deficiency, nuclear type 4
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • Cowden disease
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • mitochondrial complex II deficiency
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM1
In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 26 uncertain in NM_003000.3
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.81

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SDHBNM_003000.3 linkc.398T>C p.Met133Thr missense_variant Exon 4 of 8 ENST00000375499.8 NP_002991.2 P21912
SDHBNM_001407361.1 linkc.369+29T>C intron_variant Intron 4 of 7 NP_001394290.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SDHBENST00000375499.8 linkc.398T>C p.Met133Thr missense_variant Exon 4 of 8 1 NM_003000.3 ENSP00000364649.3 P21912

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152212
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:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251458
AF XY:
0.00
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461864
Hom.:
0
Cov.:
32
AF XY:
0.00000275
AC XY:
2
AN XY:
727232
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111994
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000656
AC:
1
AN:
152330
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74498
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41574
American (AMR)
AF:
0.00
AC:
0
AN:
15300
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Pheochromocytoma;C0238198:Gastrointestinal stromal tumor;C1861848:Pheochromocytoma/paraganglioma syndrome 4 Uncertain:1
Jan 25, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 133 of the SDHB protein (p.Met133Thr). This variant is present in population databases (rs553392349, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with SDHB-related conditions. ClinVar contains an entry for this variant (Variation ID: 569759). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt SDHB protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Gastrointestinal stromal tumor Uncertain:1
Dec 29, 2023
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1
Mar 09, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.M133T variant (also known as c.398T>C), located in coding exon 4 of the SDHB gene, results from a T to C substitution at nucleotide position 398. The methionine at codon 133 is replaced by threonine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.32
BayesDel_addAF
Pathogenic
0.45
D
BayesDel_noAF
Pathogenic
0.51
CADD
Uncertain
26
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.86
D;.;T
Eigen
Uncertain
0.48
Eigen_PC
Uncertain
0.59
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.96
D;D;D
M_CAP
Pathogenic
0.29
D
MetaRNN
Pathogenic
0.81
D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Uncertain
2.6
M;.;.
PhyloP100
8.6
PrimateAI
Pathogenic
0.83
D
PROVEAN
Pathogenic
-4.8
D;.;.
REVEL
Pathogenic
0.76
Sift
Benign
0.17
T;.;.
Sift4G
Benign
0.13
T;T;T
Polyphen
0.14
B;.;.
Vest4
0.93
MutPred
0.56
Loss of stability (P = 0.0143);.;.;
MVP
0.94
MPC
0.66
ClinPred
0.90
D
GERP RS
6.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.45
gMVP
0.93
Mutation Taster
=5/95
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.050
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs553392349; hg19: chr1-17355120; API