16-2060789-C-G

Variant names:

• chr16-2060789-C-G
• rs757135168
• NM_000548.5:c.1095C>G

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 4P and 5B. PM1 PM2 BP4_Strong BP6

The NM_000548.5(TSC2):​c.1095C>G​(p.Ile365Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,540 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. 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. I365V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: -3.03
• Publications: 2 publications found

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 Gene-Disease associations (from GenCC):

• tuberous sclerosis

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• tuberous sclerosis 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Ambry Genetics
• lymphangioleiomyomatosis

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• tuberous sclerosis complex

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

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

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 6 benign, 15 uncertain in NM_000548.5
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.041965455).
• BP6: Variant 16-2060789-C-G is Benign according to our data. Variant chr16-2060789-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 952344.We mark this variant Likely_benign, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.1095C>G	p.Ile365Met	missense_variant	Exon 11 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.1095C>G	p.Ile365Met	missense_variant	Exon 11 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461540 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727070

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53236

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111898

Other (OTH) AF: 0.00 AC: 0 AN: 60384

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis syndrome Uncertain:2

May 07, 2024

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces isoleucine with methionine at codon 365 of the TSC2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, 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. -

Aug 30, 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 isoleucine with methionine at codon 365 of the TSC2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, 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. -

Tuberous sclerosis 2 Uncertain:1

Oct 15, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine with methionine at codon 365 of the TSC2 protein (p.Ile365Met). The isoleucine residue is moderately conserved and there is a small physicochemical difference between isoleucine and methionine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with TSC2-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The methionine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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 Benign:1

May 08, 2024

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.052
BayesDel_addAF	Benign	-0.10	T
BayesDel_noAF	Benign	-0.38
CADD	Benign	0.012
DANN	Benign	0.81
DEOGEN2	Benign	0.36	T;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.7
FATHMM_MKL	Benign	0.023	N
LIST_S2	Benign	0.72	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Benign	0.0099	T
MetaRNN	Benign	0.042	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.40	N;.;.;.;N;N;.;.;.;N;.;N;.;.;.
PhyloP100		-3.0
PrimateAI	Benign	0.34	T
PROVEAN	Benign	-0.42	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Benign	0.11
Sift	Benign	0.11	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Benign	0.065	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		0.0090	B;.;.;.;B;B;.;.;B;B;.;.;.;.;.
Vest4		0.43
MutPred		0.43		Gain of MoRF binding (P = 0.1825);Gain of MoRF binding (P = 0.1825);Gain of MoRF binding (P = 0.1825);.;Gain of MoRF binding (P = 0.1825);Gain of MoRF binding (P = 0.1825);Gain of MoRF binding (P = 0.1825);Gain of MoRF binding (P = 0.1825);.;Gain of MoRF binding (P = 0.1825);Gain of MoRF binding (P = 0.1825);Gain of MoRF binding (P = 0.1825);Gain of MoRF binding (P = 0.1825);Gain of MoRF binding (P = 0.1825);.;
MVP		0.77
ClinPred		0.16	T
GERP RS		-9.2
Varity_R		0.099
gMVP		0.39
Mutation Taster		=71/29	polymorphism

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

Other links and lift over

dbSNP: rs757135168; hg19: chr16-2110790;