1-161314409-G-A

Variant names:

• chr1-161314409-G-A
• rs1198315342
• NM_003001.5:c.4G>A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_003001.5(SDHC):​c.4G>A​(p.Ala2Thr) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. A2G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SDHC NM_003001.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 4.80

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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHC	NM_003001.5	c.4G>A	p.Ala2Thr	missense_variant	Exon 1 of 6	ENST00000367975.7	NP_002992.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHC	ENST00000367975.7	c.4G>A	p.Ala2Thr	missense_variant	Exon 1 of 6	1	NM_003001.5	ENSP00000356953.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Gastrointestinal stromal tumor;C1854336:Paragangliomas 3 Uncertain:1

Jan 12, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 2 of the SDHC protein (p.Ala2Thr). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SDHC-related conditions. ClinVar contains an entry for this variant (Variation ID: 465977). 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. -

Gastrointestinal stromal tumor Uncertain:1

Aug 17, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Jan 10, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.A2T variant (also known as c.4G>A), located in coding exon 1 of the SDHC gene, results from a G to A substitution at nucleotide position 4. The alanine at codon 2 is replaced by threonine, an amino acid with similar properties. This amino acid position is highly 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	0.29
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.25
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Benign	0.14	T;.;.;.;.
Eigen	Uncertain	0.57
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Uncertain	0.87	D;D;T;T;T
M_CAP	Pathogenic	0.30	D
MetaRNN	Uncertain	0.59	D;D;D;D;D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Uncertain	2.1	M;M;M;M;M
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-1.0	N;N;N;N;N
REVEL	Uncertain	0.55
Sift	Uncertain	0.0040	D;D;D;D;D
Sift4G	Uncertain	0.011	D;D;D;D;D
Polyphen		1.0	D;B;D;D;D
Vest4		0.57
MutPred		0.30		Loss of MoRF binding (P = 0.1816);Loss of MoRF binding (P = 0.1816);Loss of MoRF binding (P = 0.1816);Loss of MoRF binding (P = 0.1816);Loss of MoRF binding (P = 0.1816);
MVP		0.95
MPC		1.1
ClinPred		0.96	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.23
gMVP		0.84

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: rs1198315342; hg19: chr1-161284199;