1-17053997-G-T

Variant names:

• chr1-17053997-G-T
• rs199848267
• NM_003000.3:c.23C>A

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_003000.3(SDHB):​c.23C>A​(p.Ser8Tyr) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,460,406 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. S8P) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SDHB NM_003000.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.26
• Publications: 2 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: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 5 benign, 47 uncertain in NM_003000.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.804

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003000.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SDHB	NM_003000.3	MANE Select	c.23C>A	p.Ser8Tyr	missense	Exon 1 of 8	NP_002991.2
	SDHB	NM_001407361.1		c.23C>A	p.Ser8Tyr	missense	Exon 1 of 8	NP_001394290.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SDHB	ENST00000375499.8	TSL:1 MANE Select	c.23C>A	p.Ser8Tyr	missense	Exon 1 of 8	ENSP00000364649.3
	SDHB	ENST00000714034.1		c.23C>A	p.Ser8Tyr	missense	Exon 1 of 9	ENSP00000519325.1
	SDHB	ENST00000485515.6	TSL:5	c.23C>A	p.Ser8Tyr	missense	Exon 1 of 8	ENSP00000519322.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460406 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726466

African (AFR) AF: 0.00 AC: 0 AN: 33446

American (AMR) AF: 0.0000224 AC: 1 AN: 44646

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26084

East Asian (EAS) AF: 0.00 AC: 0 AN: 39662

South Asian (SAS) AF: 0.00 AC: 0 AN: 86054

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53002

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5728

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111532

Other (OTH) AF: 0.00 AC: 0 AN: 60252

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Sep 10, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces serine, which is neutral and polar, with tyrosine, which is neutral and polar, at codon 8 of the SDHB protein (p.Ser8Tyr). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SDHB-related conditions. ClinVar contains an entry for this variant (Variation ID: 836497). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SDHB 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.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.36	T
Eigen	Benign	0.13
Eigen_PC	Benign	0.22
FATHMM_MKL	Benign	0.71	D
LIST_S2	Benign	0.75	T
M_CAP	Pathogenic	0.71	D
MetaRNN	Pathogenic	0.80	D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Benign	0.34	N
PhyloP100		5.3
PrimateAI	Uncertain	0.63	T
PROVEAN	Benign	-1.2	N
REVEL	Pathogenic	0.69
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.015	D
Polyphen		0.89	P
Vest4		0.68
MutPred		0.37		Loss of disorder (P = 0.001)
MVP		0.93
MPC		0.24
ClinPred		0.87	D
GERP RS		5.2
PromoterAI		-0.089	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.58
gMVP		0.66
Mutation Taster		=41/59	disease causing

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

Other links and lift over

dbSNP: rs199848267; hg19: chr1-17380492; COSMIC: COSV107480846; COSMIC: COSV107480846;