rs34599281

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM1BP6

The NM_003000.3(SDHB):c.178A>G(p.Thr60Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000967 in 1,613,972 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. T60I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00010 ( 0 hom. )

Consequence

SDHB
NM_003000.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:3

Conservation

PhyloP100: 7.24

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 1 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 15 uncertain in NM_003000.3

BP6

Variant 1-17044783-T-C is Benign according to our data. Variant chr1-17044783-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 239423.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=6, Likely_benign=1, Benign=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SDHB	NM_003000.3 linkuse as main transcript	c.178A>G	p.Thr60Ala	missense_variant	2/8	ENST00000375499.8
SDHB	NM_001407361.1 linkuse as main transcript	c.178A>G	p.Thr60Ala	missense_variant	2/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SDHB	ENST00000375499.8 linkuse as main transcript	c.178A>G	p.Thr60Ala	missense_variant	2/8	1	NM_003000.3	P1

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152206

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000327

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:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000597

AC:

AN:

251350

Hom.:

AF XY:

0.0000662

AC XY:

AN XY:

135850

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000114

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000999

AC:

146

AN:

1461766

Hom.:

Cov.:

AF XY:

0.000100

AC XY:

AN XY:

727204

show subpopulations

Gnomad4 AFR exome

AF:

0.0000597

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000696

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000121

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000657

AC:

AN:

152206

Hom.:

Cov.:

AF XY:

0.0000941

AC XY:

AN XY:

74370

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000327

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000193

Hom.:

Bravo

AF:

0.0000793

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.0000741

AC:

EpiCase

AF:

0.000273

EpiControl

AF:

0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:1Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 31, 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. -
Uncertain significance, criteria provided, single submitter	curation	Sema4, Sema4	May 26, 2021	- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital

Aug 15, 2023

- -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 27, 2024

This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 60 of the SDHB protein (p.Thr60Ala). This variant is present in population databases (rs34599281, gnomAD 0.01%). This missense change has been observed in individual(s) with adenocortical carcinoma and/or thyroid cancer (PMID: 25694510, 28819017). ClinVar contains an entry for this variant (Variation ID: 239423). 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%. 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. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 06, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with pheochromocytomas or paragangliomas, and breast or other cancers (Ni et al., 2015; Mandelker et al., 2017; Penkert et al., 2018; Duzkale et al., 2021; Garrett et al., 2022); This variant is associated with the following publications: (PMID: 25694510, 28873162, 30086788, 29510530, 28819017, 34426522, 34271781, 34906457) -

Paragangliomas 4

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Oct 11, 2019

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

Gastrointestinal stromal tumor

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genomic Research Center, Shahid Beheshti University of Medical Sciences

Dec 18, 2017

- -

Carney-Stratakis syndrome

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 28, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Hereditary pheochromocytoma-paraganglioma

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 28, 2017

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Pathogenic

0.22

BayesDel_noAF

Pathogenic

0.31

Cadd

Uncertain

Dann

Uncertain

0.99

DEOGEN2

Uncertain

0.78

D;.;T

Eigen

Uncertain

0.24

Eigen_PC

Uncertain

0.37

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Pathogenic

0.97

D;D;D

M_CAP

Pathogenic

0.34

MetaRNN

Uncertain

0.68

D;D;D

MetaSVM

Pathogenic

0.94

MutationAssessor

Uncertain

2.7

M;.;.

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.54

PROVEAN

Benign

-2.1

N;.;.

REVEL

Pathogenic

0.84

Sift

Uncertain

0.023

D;.;.

Sift4G

Benign

0.12

T;T;T

Polyphen

0.0010

B;.;.

Vest4

0.86

MVP

0.98

MPC

0.17

ClinPred

0.23

GERP RS

5.7

Varity_R

0.43

gMVP

0.63

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

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