rs201082445

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1

The NM_003000.3(SDHB):c.527A>G(p.Glu176Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000377 in 1,590,898 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. E176D) has been classified as Likely benign.

Frequency

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

Exomes 𝑓: 0.0000035 ( 0 hom. )

Consequence

SDHB
NM_003000.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 7.48

Publications

1 publications found

Variant links:

COSMIC-nc: COSV104685780

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

SDHB links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 35 uncertain in NM_003000.3

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHB	NM_003000.3 link	c.527A>G	p.Glu176Gly	missense_variant	Exon 5 of 8	ENST00000375499.8	NP_002991.2	P21912
SDHB	NM_001407361.1 link	c.473A>G	p.Glu158Gly	missense_variant	Exon 5 of 8		NP_001394290.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHB	ENST00000375499.8 link	c.527A>G	p.Glu176Gly	missense_variant	Exon 5 of 8	1	NM_003000.3	ENSP00000364649.3		P21912

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152206

Hom.:

Cov.:

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:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251406

AF XY:

0.00000736

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:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000348

AC:

AN:

1438692

Hom.:

Cov.:

AF XY:

0.00000418

AC XY:

AN XY:

717270

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32994

American (AMR)

AF:

0.00

AC:

AN:

44696

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25996

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39606

South Asian (SAS)

AF:

0.00

AC:

AN:

85742

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53344

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5722

European-Non Finnish (NFE)

AF:

0.00000367

AC:

AN:

1091008

Other (OTH)

AF:

0.00

AC:

AN:

59584

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152206

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74356

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41464

American (AMR)

AF:

0.00

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68032

Other (OTH)

AF:

0.000478

AC:

AN:

2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000508

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Feb 27, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign to our knowledge; In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; In silico analysis is inconclusive as to whether the variant alters gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; This variant is associated with the following publications: (PMID: Ertorer2023[abstract]) -

Pheochromocytoma;C0238198:Gastrointestinal stromal tumor;C1861848:Pheochromocytoma/paraganglioma syndrome 4

Uncertain:1

Jan 15, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 176 of the SDHB protein (p.Glu176Gly). This variant is present in population databases (rs201082445, gnomAD 0.0009%). 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: 459153). 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 expected to disrupt SDHB protein function with a positive 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

Feb 05, 2024

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome

Uncertain:1

Jan 03, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.E176G variant (also known as c.527A>G), located in coding exon 5 of the SDHB gene, results from an A to G substitution at nucleotide position 527. The glutamic acid at codon 176 is replaced by glycine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.39

BayesDel_addAF

Pathogenic

0.21

BayesDel_noAF

Uncertain

0.070

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.68

D;.;T

Eigen

Uncertain

0.35

Eigen_PC

Uncertain

0.45

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.97

D;D;D

M_CAP

Pathogenic

0.36

MetaRNN

Uncertain

0.65

D;D;D

MetaSVM

Pathogenic

0.92

MutationAssessor

Uncertain

2.5

M;.;.

PhyloP100

7.5

PrimateAI

Benign

0.48

PROVEAN

Uncertain

-3.5

D;.;.

REVEL

Pathogenic

0.67

Sift

Pathogenic

0.0

D;.;.

Sift4G

Pathogenic

0.0010

D;D;D

Polyphen

0.065

B;.;.

Vest4

0.43

MutPred

0.44

Loss of stability (P = 0.0777);.;.;

MVP

0.95

MPC

0.21

ClinPred

0.95

GERP RS

5.8

Varity_R

0.78

gMVP

0.78

Mutation Taster

=58/42

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.080

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over