rs876658540

Variant names:

• chr1-17024049-C-A
• rs876658540
• NM_003000.3:c.566G>T

Your query was ambiguous. Multiple possible variants found:

• chr1-17024049-C-A
• chr1-17024049-C-T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_003000.3(SDHB):​c.566G>T​(p.Cys189Phe) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C189R) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SDHB NM_003000.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.08
• Publications: 1 publications found

Genes affected

SDHB (HGNC:10681): (succinate dehydrogenase complex iron sulfur subunit B) This tumor suppressor gene encodes the iron-sulfur protein subunit of the succinate dehydrogenase (SDH) enzyme complex which plays a critical role in mitochondria. The SDH enzyme complex is composed of four nuclear-encoded subunits. This enzyme complex converts succinate to fumarate which releases electrons as part of the citric acid cycle, and the enzyme complex additionally provides an attachment site for released electrons to be transferred to the oxidative phosphorylation pathway. The SDH enzyme complex plays a role in oxygen-related gene regulation through its conversion of succinate, which is an oxygen sensor that stabilizes the hypoxia-inducible factor 1 (HIF1) transcription factor. Sporadic and familial mutations in this gene result in paragangliomas, pheochromocytoma, and gastrointestinal stromal tumors, supporting a link between mitochondrial dysfunction and tumorigenesis. Mutations in this gene are also implicated in nuclear type 4 mitochondrial complex II deficiency. [provided by RefSeq, Jun 2022]

SDHB Gene-Disease associations (from GenCC):

• Carney-Stratakis syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet
• gastrointestinal stromal tumor

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae)
• hereditary pheochromocytoma-paraganglioma

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• pheochromocytoma

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• pheochromocytoma/paraganglioma syndrome 4

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• mitochondrial disease

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• renal cell carcinoma

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• mitochondrial complex 2 deficiency, nuclear type 4

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• Cowden disease

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• mitochondrial complex II deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 33 uncertain in NM_003000.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-17024050-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 952708.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988
• PP5: Variant 1-17024049-C-A is Pathogenic according to our data. Variant chr1-17024049-C-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 230387.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHB	NM_003000.3	c.566G>T	p.Cys189Phe	missense_variant	Exon 6 of 8	ENST00000375499.8	NP_002991.2
SDHB	NM_001407361.1	c.512G>T	p.Cys171Phe	missense_variant	Exon 6 of 8		NP_001394290.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHB	ENST00000375499.8	c.566G>T	p.Cys189Phe	missense_variant	Exon 6 of 8	1	NM_003000.3	ENSP00000364649.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Pheochromocytoma;C0238198:Gastrointestinal stromal tumor;C1861848:Pheochromocytoma/paraganglioma syndrome 4 Pathogenic:1

Oct 18, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces cysteine, which is neutral and slightly polar, with phenylalanine, which is neutral and non-polar, at codon 189 of the SDHB protein (p.Cys189Phe). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with paraganglioma, gastrointestinal stromal tumor and/or pheochromocytomas (PMID: 19001511, 34906457; Invitae). ClinVar contains an entry for this variant (Variation ID: 230387). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SDHB protein function. This variant disrupts the p.Cys189 amino acid residue in SDHB. Other variant(s) that disrupt this residue have been observed in individuals with SDHB-related conditions (PMID: 27279923), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Feb 20, 2025

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.C189F variant (also known as c.566G>T), located in coding exon 6 of the SDHB gene, results from a G to T substitution at nucleotide position 566. The cysteine at codon 189 is replaced by phenylalanine, an amino acid with highly dissimilar properties. This alteration has been detected in multiple patients with a paraganglioma (Joshua AM et al. J Clin Endocrinol Metab, 2009 Jan;94:5-9; Ye L et al. Endocr Rev, 2010 Aug;31:578-99; Ambry internal data). The Cys189 residue plays a vital role coordinating the Fe4S4 cluster and it is believed that alterations at this location would prevent assembly of Complex II (Iverson TM, J. Biol. Chem. 2012 Oct; 287(42):35430-8). 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 majority of available evidence to date, this variant is likely to be pathogenic. -

Hereditary pheochromocytoma-paraganglioma Pathogenic:1

-

Section on Medical Neuroendocrinolgy, National Institutes of Health

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	33
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.93	D;.
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.70	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.89	D
MutationAssessor	Pathogenic	4.2	H;.
PhyloP100		7.1
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-10	D;.
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D;.
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.95
MutPred		0.91		Loss of sheet (P = 0.1158);.;
MVP		1.0
MPC		0.87
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.99
gMVP		0.99
Mutation Taster		=4/96	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs876658540; hg19: chr1-17350544;