rs774568101

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PM2

The NM_003000.3(SDHB):​c.440A>T​(p.Tyr147Phe) variant causes a missense change. The variant allele was found at a frequency of 0.00000124 in 1,607,112 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. Y147C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

SDHB
NM_003000.3 missense

Scores

2
11
5

Clinical Significance

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

Conservation

PhyloP100: 4.64

Publications

7 publications found
Variant links:
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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM1
In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 33 uncertain 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
SDHBNM_003000.3 linkc.440A>T p.Tyr147Phe missense_variant Exon 5 of 8 ENST00000375499.8 NP_002991.2
SDHBNM_001407361.1 linkc.386A>T p.Tyr129Phe missense_variant Exon 5 of 8 NP_001394290.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SDHBENST00000375499.8 linkc.440A>T p.Tyr147Phe missense_variant Exon 5 of 8 1 NM_003000.3 ENSP00000364649.3

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152034
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000242
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
6.87e-7
AC:
1
AN:
1455078
Hom.:
0
Cov.:
28
AF XY:
0.00
AC XY:
0
AN XY:
724334
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33364
American (AMR)
AF:
0.00
AC:
0
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26092
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39674
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86130
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53262
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5756
European-Non Finnish (NFE)
AF:
9.04e-7
AC:
1
AN:
1105930
Other (OTH)
AF:
0.00
AC:
0
AN:
60154
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
152034
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74258
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41394
American (AMR)
AF:
0.00
AC:
0
AN:
15250
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10572
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0

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
Aug 26, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C15". The phenylalanine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. This variant has not been reported in the literature in individuals with SDHB-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces tyrosine with phenylalanine at codon 147 of the SDHB protein (p.Tyr147Phe). The tyrosine residue is highly conserved and there is a small physicochemical difference between tyrosine and phenylalanine.

Hereditary cancer-predisposing syndrome Uncertain:1
Feb 22, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Y147F variant (also known as c.440A>T), located in coding exon 5 of the SDHB gene, results from an A to T substitution at nucleotide position 440. The tyrosine at codon 147 is replaced by phenylalanine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. 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
0.18
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Uncertain
0.040
CADD
Benign
23
DANN
Benign
0.97
DEOGEN2
Uncertain
0.79
D;.;T
Eigen
Benign
0.14
Eigen_PC
Uncertain
0.23
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.95
D;D;D
M_CAP
Uncertain
0.092
D
MetaRNN
Uncertain
0.74
D;D;D
MetaSVM
Uncertain
0.70
D
MutationAssessor
Benign
1.6
L;.;.
PhyloP100
4.6
PrimateAI
Uncertain
0.74
T
PROVEAN
Uncertain
-3.5
D;.;.
REVEL
Pathogenic
0.65
Sift
Uncertain
0.021
D;.;.
Sift4G
Benign
0.17
T;T;T
Vest4
0.45
ClinPred
0.94
D
GERP RS
4.8
Varity_R
0.43
gMVP
0.73
Mutation Taster
=46/54
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs774568101; hg19: chr1-17354344; API