rs1553266502

chr1-161362401-G-Achr1-161362401-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_003001.5(SDHC):c.478G>A(p.Val160Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. V160V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SDHC NM_003001.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.22

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 14 uncertain in NM_003001.5
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SDHC	NM_003001.5	c.478G>A	p.Val160Met	missense_variant	6/6	ENST00000367975.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SDHC	ENST00000367975.7	c.478G>A	p.Val160Met	missense_variant	6/6	1	NM_003001.5	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1461518 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 727058

Gnomad4 AFR exome AF: 0.00

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 Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Gastrointestinal stromal tumor;C1854336:Paragangliomas 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 12, 2023

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 160 of the SDHC protein (p.Val160Met). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with pheochromocytoma (PMID: 33397043). ClinVar contains an entry for this variant (Variation ID: 465976). 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. 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 23, 2021

The p.V160M variant (also known as c.478G>A), located in coding exon 6 of the SDHC gene, results from a G to A substitution at nucleotide position 478. The valine at codon 160 is replaced by methionine, an amino acid with highly similar properties. This alteration has been detected in a patient with unilateral pheochromocytoma (Seo SH et al. Endocrinol Metab (Seoul), 2020 12;35:909-917). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. 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	Benign	0.14
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Uncertain	0.070
Cadd	Uncertain	24
Dann	Uncertain	1.0
Eigen	Uncertain	0.43
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Benign	0.55	T;T
M_CAP	Pathogenic	0.44	D
MetaRNN	Uncertain	0.64	D;D
MetaSVM	Pathogenic	0.99	D
MutationTaster	Benign	0.95	D;D;D;N;N
PROVEAN	Benign	-0.33	N;N
REVEL	Uncertain	0.44
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		0.92	P;D
Vest4		0.56
MutPred		0.26		Gain of phosphorylation at C105 (P = 0.0605);.;
MVP		0.93
ClinPred		0.99	D
GERP RS		5.3

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

Other links and lift over

dbSNP: rs1553266502; hg19: chr1-161332191;