chr1-17028599-C-T

Variant names:

• chr1-17028599-C-T
• rs398122805
• NM_003000.3:c.423+1G>A

Variant summary

Our verdict is Pathogenic. The variant received 22 ACMG points: 22P and 0B. PVS1 PS3 PM2 PP5_Very_Strong

The NM_003000.3(SDHB):​c.423+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,762 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV000214164: RNA studies have demonstrated that this alteration abolishes the native donor site and activates a cryptic donor site in the adjacent exon (Bayley JP et al. BMC Med Genet, 2006 Jan;7:1; Ercolino T et al. J. Endocrinol. Invest., 2009 Feb;32:111-4; Ambry internal data).; SCV004838378: Experimental RNA studies have shown that this variant causes an in-frame deletion of 54 nucleotides in exon 4 resulting in deletion of 18 amino acids in the 4Fe-4S ferredoxin-type domain (PMID:19411806).; SCV000287775: Studies have shown that disruption of this splice site is associated with altered splicing resulting in multiple RNA products (internal data).".

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: SDHB NM_003000.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:15
• Conservation: PhyloP100: 7.23
• Publications: 37 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: Ambry Genetics, Genomics England PanelApp, 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 22 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 5.7, offset of -25, new splice context is: catGTatgt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PS3: PS3 evidence extracted from ClinVar submissions: SCV000214164: RNA studies have demonstrated that this alteration abolishes the native donor site and activates a cryptic donor site in the adjacent exon (Bayley JP et al. BMC Med Genet, 2006 Jan;7:1; Ercolino T et al. J. Endocrinol. Invest., 2009 Feb;32:111-4; Ambry internal data).; SCV004838378: Experimental RNA studies have shown that this variant causes an in-frame deletion of 54 nucleotides in exon 4 resulting in deletion of 18 amino acids in the 4Fe-4S ferredoxin-type domain (PMID: 19411806).; SCV000287775: Studies have shown that disruption of this splice site is associated with altered splicing resulting in multiple RNA products (internal data).
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-17028599-C-T is Pathogenic according to our data. Variant chr1-17028599-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 29896.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SDHB	NM_003000.3	MANE Select	c.423+1G>A		splice_donor intron	N/A	NP_002991.2	P21912
	SDHB	NM_001407361.1		c.369+55G>A		intron	N/A	NP_001394290.1	A0AAQ5BHD9

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SDHB	ENST00000375499.8	TSL:1 MANE Select	c.423+1G>A		splice_donor intron	N/A	ENSP00000364649.3	P21912
	SDHB	ENST00000714034.1		c.468+1G>A		splice_donor intron	N/A	ENSP00000519325.1	A0AAQ5BHC9
	SDHB	ENST00000925621.1		c.417+7G>A		splice_region intron	N/A	ENSP00000595680.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251374 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461762 Hom.: 0 Cov.: 32 AF XY: 0.00000688 AC XY: 5 AN XY: 727198

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53350

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111954

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
6	-	-	not provided (6)
3	-	-	Hereditary pheochromocytoma and paraganglioma (3)
2	-	-	Pheochromocytoma/paraganglioma syndrome 4 (2)
1	-	-	Gastrointestinal stromal tumor (1)
1	-	-	Hereditary cancer-predisposing syndrome (1)
1	-	-	Pheochromocytoma;C0238198:Gastrointestinal stromal tumor;C1861848:Pheochromocytoma/paraganglioma syndrome 4 (1)
1	-	-	Pheochromocytoma;C1847319:Carney-Stratakis syndrome;C1861848:Pheochromocytoma/paraganglioma syndrome 4 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		7.2
GERP RS		6.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.97		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.97		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs398122805; hg19: chr1-17355094; COSMIC: COSV64965540; COSMIC: COSV64965540;