1-17044888-C-G

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP4

The NM_003000.3(SDHB):c.73G>C(p.Ala25Pro) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,050 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. 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. A25S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

SDHB
NM_003000.3 missense, splice_region

Scores

Splicing: ADA: 0.8937

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.851

Publications

2 publications found

Variant links:

COSMIC-nc: COSV100973311

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

SDHB links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.3796668).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHB	NM_003000.3 link	c.73G>C	p.Ala25Pro	missense_variant, splice_region_variant	Exon 2 of 8	ENST00000375499.8	NP_002991.2
SDHB	NM_001407361.1 link	c.73G>C	p.Ala25Pro	missense_variant, splice_region_variant	Exon 2 of 8		NP_001394290.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHB	ENST00000375499.8 link	c.73G>C	p.Ala25Pro	missense_variant, splice_region_variant	Exon 2 of 8	1	NM_003000.3	ENSP00000364649.3

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

151866

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000800

AC:

AN:

249888

AF XY:

0.00000740

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000885

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000342

AC:

AN:

1461184

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

726910

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33446

American (AMR)

AF:

0.0000224

AC:

AN:

44704

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39694

South Asian (SAS)

AF:

0.00

AC:

AN:

86208

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53000

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000360

AC:

AN:

1111866

Other (OTH)

AF:

0.00

AC:

AN:

60366

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.435

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000658

AC:

AN:

151866

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74160

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41296

American (AMR)

AF:

0.00

AC:

AN:

15252

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5180

South Asian (SAS)

AF:

0.00

AC:

AN:

4810

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10564

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67984

Other (OTH)

AF:

0.00

AC:

AN:

2084

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

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

Uncertain:1

Nov 13, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 25 of the SDHB protein (p.Ala25Pro). This variant is present in population databases (rs768101924, gnomAD 0.003%). 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: 459170). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant¬¨‚Ä†is likely to be tolerated. RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (internal data). 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.

Hereditary cancer-predisposing syndrome

Uncertain:1

Nov 02, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.A25P variant (also known as c.73G>C) is located in coding exon 2 of the SDHB gene. The alanine at codon 25 is replaced by proline, an amino acid with highly similar properties. This change occurs in the first base pair of coding exon 2. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Uncertain

0.040

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.35

T;.

Eigen

Benign

-0.31

Eigen_PC

Benign

-0.16

FATHMM_MKL

Uncertain

0.91

LIST_S2

Benign

0.72

T;T

M_CAP

Uncertain

0.12

MetaRNN

Benign

0.38

T;T

MetaSVM

Uncertain

0.70

MutationAssessor

Benign

1.1

L;.

PhyloP100

0.85

PrimateAI

Uncertain

0.51

PROVEAN

Benign

-0.89

N;.

REVEL

Pathogenic

0.66

Sift

Benign

0.13

T;.

Sift4G

Benign

0.10

T;T

Vest4

0.67

ClinPred

0.16

GERP RS

4.7

PromoterAI

-0.0084

Neutral

(source)

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.9

Varity_R

0.11

gMVP

0.57

Mutation Taster

=52/48

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.89

dbscSNV1_RF

Pathogenic

0.79

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over