rs140178341

Positions:

chr1-17028716-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1PM2

The NM_003000.3(SDHB):c.307A>G(p.Met103Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000508 in 1,614,050 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M103I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000051 ( 0 hom. )

Consequence

SDHB
NM_003000.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7B:1

Conservation

PhyloP100: 7.33

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM1

In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 uncertain in NM_003000.3

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SDHB	NM_003000.3 linkuse as main transcript	c.307A>G	p.Met103Val	missense_variant	4/8	ENST00000375499.8
SDHB	NM_001407361.1 linkuse as main transcript	c.307A>G	p.Met103Val	missense_variant	4/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SDHB	ENST00000375499.8 linkuse as main transcript	c.307A>G	p.Met103Val	missense_variant	4/8	1	NM_003000.3	P1

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152214

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.0000588

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000183

AC:

AN:

251412

Hom.:

AF XY:

0.000140

AC XY:

AN XY:

135886

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.000954

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000163

Gnomad SAS exome

AF:

0.0000653

Gnomad FIN exome

AF:

0.0000463

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.000326

GnomAD4 exome

AF:

0.0000513

AC:

AN:

1461836

Hom.:

Cov.:

AF XY:

0.0000509

AC XY:

AN XY:

727218

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000939

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000756

Gnomad4 SAS exome

AF:

0.0000348

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.0000216

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74360

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.000478

Alfa

AF:

0.0000382

Hom.:

Bravo

AF:

0.000106

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000132

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:7Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Gastrointestinal stromal tumor

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Mendelics	May 28, 2019	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 22, 2024	- -

Pheochromocytoma;C1847319:Carney-Stratakis syndrome;C1861848:Paragangliomas 4

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Pheochromocytoma

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Sep 10, 2019

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

Pheochromocytoma;C0238198:Gastrointestinal stromal tumor;C1861848:Paragangliomas 4

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 30, 2024

This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 103 of the SDHB protein (p.Met103Val). This variant is present in population databases (rs140178341, gnomAD 0.1%). This missense change has been observed in individual(s) with pheochromocytomas and paragangliomas (PMID: 34906457). ClinVar contains an entry for this variant (Variation ID: 239429). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SDHB protein function with a negative predictive value of 80%. RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (Invitae). 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. -

Paragangliomas 4

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

St. Jude Molecular Pathology, St. Jude Children's Research Hospital

Sep 29, 2022

The SDHB c.307A>G (p.Met103Val) missense change has a maximum frequency of 0.095% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/ ). The in silico tool REVEL predicts a deleterious effect on protein function, but to our knowledge this prediction has not been confirmed by functional studies. To our knowledge, this variant has not been reported in individuals with hereditary paraganglioma-pheochromocytoma. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

May 17, 2023

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in an individual with paraganglioma/pheochromocytoma (Garrett et al., 2022); This variant is associated with the following publications: (PMID: 29684080, 32948195, 34906457) -

Hereditary cancer-predisposing syndrome

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 04, 2019

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.36

BayesDel_addAF

Pathogenic

0.24

BayesDel_noAF

Pathogenic

0.52

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.81

D;.;T

Eigen

Pathogenic

0.69

Eigen_PC

Pathogenic

0.73

FATHMM_MKL

Uncertain

0.95

LIST_S2

Pathogenic

0.98

D;D;D

M_CAP

Uncertain

0.28

MetaRNN

Uncertain

0.62

D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.1

M;.;.

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.77

PROVEAN

Uncertain

-3.7

D;.;.

REVEL

Pathogenic

0.85

Sift

Pathogenic

0.0

D;.;.

Sift4G

Uncertain

0.033

D;D;D

Polyphen

0.77

P;.;.

Vest4

0.83

MVP

0.98

MPC

0.47

ClinPred

0.35

GERP RS

6.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.88

gMVP

0.84

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

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.

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