1-161356809-T-G

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1PM2PP3_ModeratePP5_Very_Strong

The NM_003001.5(SDHC):c.374T>G(p.Met125Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,614,042 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M125I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SDHC
NM_003001.5 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 0.403

Variant links:

Genes affected

SDHC (HGNC:10682): (succinate dehydrogenase complex subunit C) This gene encodes one of four nuclear-encoded subunits that comprise succinate dehydrogenase, also known as mitochondrial complex II, a key enzyme complex of the tricarboxylic acid cycle and aerobic respiratory chains of mitochondria. The encoded protein is one of two integral membrane proteins that anchor other subunits of the complex, which form the catalytic core, to the inner mitochondrial membrane. There are several related pseudogenes for this gene on different chromosomes. Mutations in this gene have been associated with paragangliomas. Alternatively spliced transcript variants have been described. [provided by RefSeq, May 2013]

SDHC links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 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, 15 uncertain in NM_003001.5

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 1-161356809-T-G is Pathogenic according to our data. Variant chr1-161356809-T-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 407057.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
SDHC	NM_003001.5 link	c.374T>G	p.Met125Arg	missense_variant	Exon 5 of 6	ENST00000367975.7	NP_002992.1	Q99643-1A0A0S2Z4B7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHC	ENST00000367975.7 link	c.374T>G	p.Met125Arg	missense_variant	Exon 5 of 6	1	NM_003001.5	ENSP00000356953.3		Q99643-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152172

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461870

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727240

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

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:

AN:

152172

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74344

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Gastrointestinal stromal tumor;C1854336:Paragangliomas 3

Pathogenic:1

Apr 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 125 of the SDHC protein (p.Met125Arg). This variant is present in population databases (no rsID available, gnomAD 0.01%). This missense change has been observed in individuals with paraganglioma and pheochromocytoma (PMID: 23512077, 30877234; Invitae). ClinVar contains an entry for this variant (Variation ID: 407057). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (Invitae). For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome

Pathogenic:1

Oct 17, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.374T>G (p.M125R) alteration is located in exon 5 (coding exon 5) of the SDHC gene. This alteration results from a T to G substitution at nucleotide position 374, causing the methionine (M) at amino acid position 125 to be replaced by an arginine (R). Based on data from gnomAD, the G allele has an overall frequency of 0.003% (1/31390) total alleles studied. The highest observed frequency was 0.012% (1/8708) of African alleles. This variant has been detected in multiple individuals with paraganglioma(s) (Fishbein, 2013; Ben Aim, 2019; Ambry internal data; external communication). This amino acid position is well conserved in available vertebrate species. This amino acid alteration is predicted to be deleterious by in silico analysis. In silico splice site analysis predicts that this nucleotide alteration will result in the creation or strengthening of a novel splice acceptor site; however RNA studies have demonstrated that this alteration does not result in abnormal splicing in the set of samples tested (Ambry internal data). Based on the available evidence, this alteration is classified as pathogenic. -

Hereditary pheochromocytoma-paraganglioma

Pathogenic:1

Aug 08, 2023

All of Us Research Program, National Institutes of Health

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces methionine with arginine at codon 125 of the SDHC protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Splice site prediction tools suggest that this variant may impact RNA splicing, however RNA studies have not been reported for this variant. This variant has been reported in multiple individuals affected with paraganglioma and pheochromocytoma (PMID: 23512077, 36091175, 30877234). This variant has been identified in 1/31390 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.82

BayesDel_addAF

Pathogenic

0.30

BayesDel_noAF

Pathogenic

0.20

CADD

Pathogenic

DANN

Benign

0.97

DEOGEN2

Benign

0.27

T;.;.

Eigen

Benign

0.12

Eigen_PC

Benign

0.073

FATHMM_MKL

Benign

0.65

LIST_S2

Uncertain

0.91

D;D;D

M_CAP

Pathogenic

0.32

MetaRNN

Pathogenic

0.96

D;D;D

MetaSVM

Uncertain

0.15

MutationAssessor

Uncertain

2.8

M;.;.

PrimateAI

Uncertain

0.55

PROVEAN

Benign

-2.0

N;N;N

REVEL

Pathogenic

0.73

Sift

Benign

0.094

T;T;T

Sift4G

Benign

0.34

T;T;T

Polyphen

0.91

P;P;P

Vest4

0.80

MutPred

0.88

Gain of catalytic residue at M125 (P = 5e-04);.;.;

MVP

0.91

MPC

1.0

ClinPred

0.92

GERP RS

1.6

Varity_R

0.55

gMVP

0.91

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.90

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.90

Position offset: 1

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