chr1-17033098-A-C

Position:

• chr1-17033098-A-C

Variant summary

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

The NM_003000.3(SDHB):​c.248T>G​(p.Val83Gly) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,694 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • 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: 6.28

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a chain Succinate dehydrogenase [ubiquinone] iron-sulfur subunit, mitochondrial (size 251) in uniprot entity SDHB_HUMAN there are 96 pathogenic changes around while only 7 benign (93%) in NM_003000.3
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SDHB	NM_003000.3	c.248T>G	p.Val83Gly	missense_variant	3/8	ENST00000375499.8	NP_002991.2
SDHB	NM_001407361.1	c.248T>G	p.Val83Gly	missense_variant	3/8		NP_001394290.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SDHB	ENST00000375499.8	c.248T>G	p.Val83Gly	missense_variant	3/8	1	NM_003000.3	ENSP00000364649	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251372 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135874

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461694 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 727160

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Pheochromocytoma;C0238198:Gastrointestinal stromal tumor;C1861848:Paragangliomas 4 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 31, 2022

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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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 not expected to disrupt SDHB protein function. ClinVar contains an entry for this variant (Variation ID: 837349). This variant has not been reported in the literature in individuals affected with SDHB-related conditions. This variant is present in population databases (rs763547482, gnomAD 0.003%). This sequence change replaces valine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 83 of the SDHB protein (p.Val83Gly). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	0.050
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.78	D;.;T
Eigen	Benign	0.12
Eigen_PC	Benign	0.22
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D;D;D
M_CAP	Uncertain	0.22	D
MetaRNN	Uncertain	0.52	D;D;D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Uncertain	2.7	M;.;.
MutationTaster	Benign	1.0	D
PrimateAI	Benign	0.45	T
PROVEAN	Uncertain	-3.9	D;.;.
REVEL	Uncertain	0.55
Sift	Benign	0.030	D;.;.
Sift4G	Benign	0.20	T;T;T
Polyphen		0.026	B;.;.
Vest4		0.36
MutPred		0.47		Loss of stability (P = 0.0019);.;.;
MVP		0.93
MPC		0.22
ClinPred		0.51	D
GERP RS		5.4
Varity_R		0.50
gMVP		0.71

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs763547482; hg19: chr1-17359593;