1-161340640-A-G

Position:

• chr1-161340640-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_003001.5(SDHC):​c.226A>G​(p.Ile76Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SDHC NM_003001.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -3.42

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in NM_003001.5
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1222845).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SDHC	NM_003001.5	c.226A>G	p.Ile76Val	missense_variant	4/6	ENST00000367975.7	NP_002992.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SDHC	ENST00000367975.7	c.226A>G	p.Ile76Val	missense_variant	4/6	1	NM_003001.5	ENSP00000356953.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Gastrointestinal stromal tumor;C1854336:Paragangliomas 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 10, 2023

ClinVar contains an entry for this variant (Variation ID: 407051). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. This variant has not been reported in the literature in individuals affected with SDHC-related conditions. This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 76 of the SDHC protein (p.Ile76Val). This variant is not present in population databases (gnomAD no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.079
BayesDel_addAF	Benign	-0.025	T
BayesDel_noAF	Benign	-0.27
CADD	Benign	0.019
DANN	Benign	0.65
DEOGEN2	Benign	0.11	T;.;.;.;.
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.0
FATHMM_MKL	Benign	0.012	N
LIST_S2	Benign	0.81	T;T;T;T;T
M_CAP	Benign	0.036	D
MetaRNN	Benign	0.12	T;T;T;T;T
MetaSVM	Benign	-0.71	T
MutationAssessor	Benign	-0.45	N;N;.;.;.
PrimateAI	Benign	0.32	T
PROVEAN	Benign	0.0	N;N;N;N;N
REVEL	Uncertain	0.32
Sift	Benign	0.90	T;T;T;T;T
Sift4G	Benign	0.95	T;T;T;T;T
Polyphen		0.0	B;B;B;B;B
Vest4		0.062
MutPred		0.55		Gain of methylation at R72 (P = 0.1147);Gain of methylation at R72 (P = 0.1147);.;.;.;
MVP		0.66
MPC		0.30
ClinPred		0.038	T
GERP RS		-2.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.018
gMVP		0.45

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: rs1060501389; hg19: chr1-161310430;