rs1060503752

chr1-17023993-CCA-C

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1 PP5_Moderate

The NM_003000.3(SDHB):c.620_621del(p.Leu207ArgfsTer14) variant causes a frameshift change involving the alteration of a conserved nucleotide. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. L207L) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SDHB NM_003000.3 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.31

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 Pathogenic. Variant got 10 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PP5: Variant 1-17023993-CCA-C is Pathogenic according to our data. Variant chr1-17023993-CCA-C is described in ClinVar as [Pathogenic]. Clinvar id is 412454.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr1-17023993-CCA-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SDHB	NM_003000.3	c.620_621del	p.Leu207ArgfsTer14	frameshift_variant	6/8	ENST00000375499.8
SDHB	NM_001407361.1	c.566_567del	p.Leu189ArgfsTer14	frameshift_variant	6/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SDHB	ENST00000375499.8	c.620_621del	p.Leu207ArgfsTer14	frameshift_variant	6/8	1	NM_003000.3	P1
SDHB	ENST00000463045.3	c.449_450del	p.Leu150ArgfsTer14	frameshift_variant	6/8	3
SDHB	ENST00000491274.6	c.578_579del	p.Leu193ArgfsTer14	frameshift_variant	6/8	5
SDHB	ENST00000485515.5	n.554_555del		non_coding_transcript_exon_variant	6/7	5

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Mar 02, 2023

This sequence change creates a premature translational stop signal (p.Leu207Argfs*14) in the SDHB gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in SDHB are known to be pathogenic (PMID: 19454582, 19802898). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with pheochromocytomas (PCC) and/or paragangliomas (PGL) (PMID: 14500403, 16314641, 19454582, 25405498, 30877234). This variant is also known as 754–755 del TG. ClinVar contains an entry for this variant (Variation ID: 412454). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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: rs1060503752; hg19: chr1-17350488;