1-161328467-G-T

Variant names:

• chr1-161328467-G-T
• rs769177037
• NM_003001.5:c.149G>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_003001.5(SDHC):​c.149G>T​(p.Arg50Leu) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,460,316 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R50H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SDHC NM_003001.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.95
• Publications: 4 publications found

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 Gene-Disease associations (from GenCC):

• hereditary pheochromocytoma-paraganglioma

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• pheochromocytoma/paraganglioma syndrome 3

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• Carney-Stratakis syndrome

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
• gastrointestinal stromal tumor

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• renal cell carcinoma

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• Cowden disease

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• mitochondrial disease

  Inheritance: Unknown Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 34 uncertain in NM_003001.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-161328466-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 135194.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.989

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHC	NM_003001.5	c.149G>T	p.Arg50Leu	missense_variant	Exon 3 of 6	ENST00000367975.7	NP_002992.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHC	ENST00000367975.7	c.149G>T	p.Arg50Leu	missense_variant	Exon 3 of 6	1	NM_003001.5	ENSP00000356953.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460316 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726632

African (AFR) AF: 0.0000299 AC: 1 AN: 33448

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26112

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86236

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110608

Other (OTH) AF: 0.00 AC: 0 AN: 60336

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Mar 05, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R50L variant (also known as c.149G>T), located in coding exon 3 of the SDHC gene, results from a G to T substitution at nucleotide position 149. The arginine at codon 50 is replaced by leucine, an amino acid with dissimilar 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. Based on the available evidence, the clinical significance of this variant remains unclear. -

Gastrointestinal stromal tumor;C1854336:Pheochromocytoma/paraganglioma syndrome 3 Uncertain:1

Feb 22, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with an SDHC-related disease. In summary, this variant is a rare missense change with uncertain impact on protein function. While it is absent from the population and affects an amino acid residue important for protein function, the available evidence is currently insufficient to determine its role in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). A different missense substitution at this codon (p.Arg50Cys) has been determined to be likely pathogenic (PMID: 23175444, 27279923, 24102379, 19351833, 23666964, Invitae database). This suggests that the arginine residue is critical for SDHC protein function and that other missense substitutions at this position may also be pathogenic. This sequence change replaces arginine with leucine at codon 50 of the SDHC protein (p.Arg50Leu). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.88
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.72	D;.
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Pathogenic	0.66	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.2	H;H
PhyloP100		7.0
PrimateAI	Benign	0.46	T
PROVEAN	Pathogenic	-5.5	D;D
REVEL	Pathogenic	0.96
Sift	Uncertain	0.0040	D;D
Sift4G	Uncertain	0.0040	D;D
Polyphen		1.0	D;D
Vest4		0.92
MutPred		0.88		Loss of disorder (P = 0.0586);Loss of disorder (P = 0.0586);
MVP		0.98
MPC		1.3
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.86
gMVP		0.98
Mutation Taster		=13/87	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs769177037; hg19: chr1-161298257;