chr16-2071864-G-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_000548.5(TSC2):​c.2027G>T​(p.Gly676Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000534 in 1,328,766 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.000053 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

2
6
11

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:1

Conservation

PhyloP100: 2.10
Variant links:
Genes affected
TSC2 (HGNC:12363): (TSC complex subunit 2) This gene is a tumor suppressor gene that encodes the growth inhibitory protein tuberin. Tuberin interacts with hamartin to form the TSC protein complex which functions in the control of cell growth. This TSC protein complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BS2
High AC in GnomAdExome4 at 71 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
TSC2NM_000548.5 linkuse as main transcriptc.2027G>T p.Gly676Val missense_variant 19/42 ENST00000219476.9 NP_000539.2 P49815-1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
TSC2ENST00000219476.9 linkuse as main transcriptc.2027G>T p.Gly676Val missense_variant 19/425 NM_000548.5 ENSP00000219476.3 P49815-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD3 exomes
AF:
0.0000196
AC:
2
AN:
102112
Hom.:
0
AF XY:
0.0000364
AC XY:
2
AN XY:
54932
show subpopulations
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 SAS exome
AF:
0.0000708
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000263
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000534
AC:
71
AN:
1328766
Hom.:
0
Cov.:
33
AF XY:
0.0000568
AC XY:
37
AN XY:
651664
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000310
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000648
Gnomad4 OTH exome
AF:
0.0000182
GnomAD4 genome
Cov.:
33
ExAC
AF:
0.00000877
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:4Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1Benign:1
Uncertain significance, criteria provided, single submitterclinical testingGenome-Nilou LabNov 07, 2021- -
Benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpNov 27, 2023- -
Tuberous sclerosis syndrome Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAll of Us Research Program, National Institutes of HealthDec 18, 2023This missense variant replaces glycine with valine at codon 676 of the TSC2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with TSC2-related disorders in the literature. This variant has been identified in 2/102112 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingGeneDxFeb 11, 2022In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
Hereditary cancer-predisposing syndrome Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsJun 10, 2024The p.G676V variant (also known as c.2027G>T), located in coding exon 18 of the TSC2 gene, results from a G to T substitution at nucleotide position 2027. The glycine at codon 676 is replaced by valine, an amino acid with dissimilar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.080
BayesDel_addAF
Pathogenic
0.17
D
BayesDel_noAF
Uncertain
0.0
CADD
Benign
22
DANN
Benign
0.96
DEOGEN2
Uncertain
0.51
D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen
Benign
-0.31
Eigen_PC
Benign
-0.22
FATHMM_MKL
Benign
0.64
D
LIST_S2
Uncertain
0.86
D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP
Pathogenic
0.36
D
MetaRNN
Uncertain
0.66
D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
-0.27
T
MutationAssessor
Benign
0.69
N;.;.;.;N;N;.;.;.;N;.;N;.;.;.
MutationTaster
Benign
0.64
N;N;N;N;N;N;N
PrimateAI
Benign
0.46
T
PROVEAN
Benign
-1.3
N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL
Uncertain
0.51
Sift
Benign
0.42
T;.;.;T;.;T;.;.;T;D;.;.;.;.;T
Sift4G
Benign
0.17
T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen
0.78
P;.;.;.;B;B;.;.;B;B;.;.;.;.;.
Vest4
0.35
MutPred
0.74
Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);.;Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);.;Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);.;
MVP
0.97
ClinPred
0.21
T
GERP RS
4.4
Varity_R
0.058
gMVP
0.42

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs754556513; hg19: chr16-2121865; API