16-2058823-C-T

Position:

chr16-2058823-C-T

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP6BS2

The NM_000548.5(TSC2):c.925C>T(p.Leu309Phe) variant causes a missense change. The variant allele was found at a frequency of 0.00000964 in 1,452,152 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. L309Q) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:2

Conservation

PhyloP100: 4.71

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

BP6

Variant 16-2058823-C-T is Benign according to our data. Variant chr16-2058823-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 468192.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=3}.

BS2

High AC in GnomAdExome4 at 14 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC2	NM_000548.5 linkuse as main transcript	c.925C>T	p.Leu309Phe	missense_variant	10/42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9 linkuse as main transcript	c.925C>T	p.Leu309Phe	missense_variant	10/42	5	NM_000548.5	ENSP00000219476		P49815-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000429

AC:

AN:

233352

Hom.:

AF XY:

0.00

AC XY:

AN XY:

125984

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:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000958

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000964

AC:

AN:

1452152

Hom.:

Cov.:

AF XY:

0.00000832

AC XY:

AN XY:

721254

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:

0.0000126

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000624

Hom.:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Department of Pathology and Laboratory Medicine, Sinai Health System	-	The TSC2 p.Leu309Phe variant was not identified in the literature nor was it identified in Cosmic. The variant was identified in dbSNP (ID: rs1258567486) and ClinVar (classified as likely benign by Invitae and uncertain significance by Ambry Genetics). The variant was identified in control databases in 1 of 221912 chromosomes at a frequency of 0.000004506 (Genome Aggregation Database March 6, 2019, v2.1.1). The variant was observed in the European (non-Finnish) population in 1 of 95764 chromosomes (freq: 0.00001), but was not observed in the African, Latino, Ashkenazi Jewish, East Asian, European (Finnish), Other, or South Asian populations. The p.Leu309 residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Sep 12, 2023	In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Tuberous sclerosis 2

Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Likely benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 28, 2023	- -

Tuberous sclerosis syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Aug 15, 2023

This missense variant replaces leucine with phenylalanine at codon 309 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 1/233352 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. -

Hereditary cancer-predisposing syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 14, 2023

The p.L309F variant (also known as c.925C>T), located in coding exon 9 of the TSC2 gene, results from a C to T substitution at nucleotide position 925. The leucine at codon 309 is replaced by phenylalanine, an amino acid with highly similar properties. This amino acid position is highly 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

Pathogenic

0.70

BayesDel_addAF

Pathogenic

0.24

BayesDel_noAF

Uncertain

0.11

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.75

D;.;.;.;.;.;.;.;.;.;.;.;T;.;T

Eigen

Uncertain

0.49

Eigen_PC

Uncertain

0.40

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.89

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

M_CAP

Pathogenic

0.35

MetaRNN

Uncertain

0.50

T;T;T;T;T;T;T;T;T;T;T;T;T;T;T

MetaSVM

Uncertain

0.25

MutationAssessor

Uncertain

2.1

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

MutationTaster

Benign

1.0

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

PrimateAI

Uncertain

0.71

PROVEAN

Uncertain

-2.4

N;.;.;N;.;N;.;.;N;N;.;.;.;.;N

REVEL

Uncertain

0.52

Sift

Uncertain

0.0080

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

Sift4G

Uncertain

0.011

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

Polyphen

1.0

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

Vest4

0.74

MutPred

0.33

Loss of helix (P = 0.0626);Loss of helix (P = 0.0626);Loss of helix (P = 0.0626);.;Loss of helix (P = 0.0626);Loss of helix (P = 0.0626);Loss of helix (P = 0.0626);Loss of helix (P = 0.0626);.;Loss of helix (P = 0.0626);Loss of helix (P = 0.0626);Loss of helix (P = 0.0626);Loss of helix (P = 0.0626);Loss of helix (P = 0.0626);.;

MVP

0.62

ClinPred

0.80

GERP RS

5.1

Varity_R

0.34

gMVP

0.44

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

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.

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