1-17027801-G-C

Variant names:

• chr1-17027801-G-C
• rs769687734
• NM_003000.3:c.488C>G

Variant summary

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

The NM_003000.3(SDHB):​c.488C>G​(p.Ser163Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S163P) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SDHB NM_003000.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.51

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 region_of_interest Interaction with SDHAF1 (size 72) in uniprot entity SDHB_HUMAN there are 66 pathogenic changes around while only 2 benign (97%) in NM_003000.3
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHB	NM_003000.3	c.488C>G	p.Ser163Cys	missense_variant	Exon 5 of 8	ENST00000375499.8	NP_002991.2
SDHB	NM_001407361.1	c.434C>G	p.Ser145Cys	missense_variant	Exon 5 of 8		NP_001394290.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHB	ENST00000375499.8	c.488C>G	p.Ser163Cys	missense_variant	Exon 5 of 8	1	NM_003000.3	ENSP00000364649.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Uncertain	26
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.53	D;.;T
Eigen	Uncertain	0.38
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D;D
M_CAP	Uncertain	0.21	D
MetaRNN	Uncertain	0.53	D;D;D
MetaSVM	Uncertain	0.74	D
MutationAssessor	Uncertain	2.7	M;.;.
PrimateAI	Uncertain	0.50	T
PROVEAN	Benign	-1.6	N;.;.
REVEL	Uncertain	0.55
Sift	Uncertain	0.021	D;.;.
Sift4G	Uncertain	0.0090	D;D;D
Polyphen		0.29	B;.;.
Vest4		0.52
MutPred		0.34		Loss of phosphorylation at S163 (P = 0.0243);.;.;
MVP		0.96
MPC		0.19
ClinPred		0.88	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.23
gMVP		0.74

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

Publications

LitVar

Other links and lift over

dbSNP: rs769687734; hg19: chr1-17354296;