16-2072361-A-G

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 6P and 4B. PM1PM5PP3_ModerateBS2

The NM_000548.5(TSC2):c.2218A>G(p.Met740Val) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000274 in 1,461,644 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M740I) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense, splice_region

Scores

Splicing: ADA: 0.6144

Clinical Significance

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

Conservation

PhyloP100: 6.08

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]

TSC2 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 9 benign, 16 uncertain in NM_000548.5

PM5

Other missense variant is known to change same aminoacid residue: Variant chr16-2072363-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1686682.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=2}.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.889

BS2

High AC in GnomAdExome4 at 40 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5 link	c.2218A>G	p.Met740Val	missense_variant, splice_region_variant	Exon 20 of 42	ENST00000219476.9	NP_000539.2	P49815-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9 link	c.2218A>G	p.Met740Val	missense_variant, splice_region_variant	Exon 20 of 42	5	NM_000548.5	ENSP00000219476.3		P49815-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.0000274

AC:

AN:

1461644

Hom.:

Cov.:

AF XY:

0.0000193

AC XY:

AN XY:

727098

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000351

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Tuberous sclerosis syndrome

Uncertain:1

Jul 20, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces methionine with valine at codon 740 of the TSC2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 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 not been identified 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. -

Lymphangiomyomatosis;C1846385:Isolated focal cortical dysplasia type II;C1860707:Tuberous sclerosis 2

Uncertain:1

Jan 13, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Uncertain:1

Sep 16, 2018

Gharavi Laboratory, Columbia University

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: research

- -

Hereditary cancer-predisposing syndrome

Uncertain:1

Mar 01, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.M740V variant (also known as c.2218A>G), located in coding exon 19 of the TSC2 gene, results from an A to G substitution at nucleotide position 2218. The methionine at codon 740 is replaced by valine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Tuberous sclerosis 2

Benign:1

Jul 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.24

BayesDel_addAF

Pathogenic

0.40

BayesDel_noAF

Pathogenic

0.33

CADD

Uncertain

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.76

D;.;.;.;.;.;.;.;.;.;.;.;D;.;D

Eigen

Uncertain

0.54

Eigen_PC

Uncertain

0.50

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.88

D;D;D;D;D;D;D;D;D;D;D;D;D;D;D

M_CAP

Pathogenic

0.38

MetaRNN

Pathogenic

0.89

D;D;D;D;D;D;D;D;D;D;D;D;D;D;D

MetaSVM

Uncertain

0.60

MutationAssessor

Uncertain

2.6

M;.;.;.;M;M;.;.;.;M;.;M;.;.;.

PrimateAI

Uncertain

0.61

PROVEAN

Uncertain

-3.0

D;.;.;D;.;D;.;.;D;D;.;.;.;.;D

REVEL

Pathogenic

0.82

Sift

Uncertain

0.0020

D;.;.;D;.;D;.;.;D;D;.;.;.;.;D

Sift4G

Uncertain

0.0060

D;.;.;D;.;D;.;.;D;D;.;.;.;.;D

Polyphen

0.73

P;.;.;.;P;P;.;.;D;D;.;.;.;.;.

Vest4

0.56

MutPred

0.72

Loss of disorder (P = 0.1227);Loss of disorder (P = 0.1227);Loss of disorder (P = 0.1227);.;Loss of disorder (P = 0.1227);Loss of disorder (P = 0.1227);Loss of disorder (P = 0.1227);Loss of disorder (P = 0.1227);.;Loss of disorder (P = 0.1227);Loss of disorder (P = 0.1227);Loss of disorder (P = 0.1227);Loss of disorder (P = 0.1227);Loss of disorder (P = 0.1227);.;

MVP

0.90

ClinPred

0.93

GERP RS

5.2

Varity_R

0.70

gMVP

0.57

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.61

dbscSNV1_RF

Benign

0.41

SpliceAI score (max)

0.29

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.29

Position offset: 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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over