rs1457574786

Positions:

• chr1-161328412-A-G

Variant summary

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

The ENST00000367975.7(SDHC):​c.94A>G​(p.Thr32Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,460,766 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. T32N) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SDHC ENST00000367975.7 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.50

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 topological_domain Mitochondrial matrix (size 32) in uniprot entity C560_HUMAN there are 8 pathogenic changes around while only 1 benign (89%) in ENST00000367975.7
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SDHC	NM_003001.5	c.94A>G	p.Thr32Ala	missense_variant	3/6	ENST00000367975.7	NP_002992.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SDHC	ENST00000367975.7	c.94A>G	p.Thr32Ala	missense_variant	3/6	1	NM_003001.5	ENSP00000356953	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251476 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135918

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460766 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726768

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

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

Labcorp Genetics (formerly Invitae), Labcorp

Aug 07, 2023

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. 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. ClinVar contains an entry for this variant (Variation ID: 465980). This variant has not been reported in the literature in individuals affected with SDHC-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.0009%). This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 32 of the SDHC protein (p.Thr32Ala). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 27, 2023

The p.T32A variant (also known as c.94A>G), located in coding exon 3 of the SDHC gene, results from an A to G substitution at nucleotide position 94. The threonine at codon 32 is replaced by alanine, an amino acid with similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. 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	0.12
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.23	T;.
Eigen	Uncertain	0.56
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Uncertain	0.88	D;D
M_CAP	Pathogenic	0.47	D
MetaRNN	Uncertain	0.47	T;T
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Uncertain	2.5	M;M
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-2.1	N;N
REVEL	Uncertain	0.63
Sift	Benign	0.057	T;D
Sift4G	Uncertain	0.015	D;D
Polyphen		0.86	P;D
Vest4		0.29
MutPred		0.29		Loss of catalytic residue at T32 (P = 0.0739);Loss of catalytic residue at T32 (P = 0.0739);
MVP		0.97
MPC		0.87
ClinPred		0.91	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.15
gMVP		0.88

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1457574786; hg19: chr1-161298202;