16-2071914-C-T

Variant names:

• chr16-2071914-C-T
• rs1167258871
• NM_000548.5:c.2077C>T

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_Moderate BP6 BP7 BS2

The NM_000548.5(TSC2):​c.2077C>T​(p.Leu693Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000126 in 1,591,604 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. L693L) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000013 (0 hom.)
• Consequence: TSC2 NM_000548.5 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:5
• Conservation: PhyloP100: 2.31
• Publications: 7 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: Benign. The variant received -8 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.45).
• BP6: Variant 16-2071914-C-T is Benign according to our data. Variant chr16-2071914-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 467921.
• BP7: Synonymous conserved (PhyloP=2.31 with no splicing effect.
• BS2: High AC in GnomAdExome4 at 19 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000548.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TSC2	NM_000548.5	MANE Select	c.2077C>T	p.Leu693Leu	synonymous	Exon 19 of 42	NP_000539.2
	TSC2	NM_001406663.1		c.2077C>T	p.Leu693Leu	synonymous	Exon 19 of 42	NP_001393592.1
	TSC2	NM_001114382.3		c.2077C>T	p.Leu693Leu	synonymous	Exon 19 of 41	NP_001107854.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TSC2	ENST00000219476.9	TSL:5 MANE Select	c.2077C>T	p.Leu693Leu	synonymous	Exon 19 of 42	ENSP00000219476.3
	TSC2	ENST00000350773.9	TSL:1	c.2077C>T	p.Leu693Leu	synonymous	Exon 19 of 41	ENSP00000344383.4
	TSC2	ENST00000401874.7	TSL:1	c.2077C>T	p.Leu693Leu	synonymous	Exon 19 of 40	ENSP00000384468.2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152284 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

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: 0.0000132 AC: 19 AN: 1439320 Hom.: 0 Cov.: 33 AF XY: 0.0000126 AC XY: 9 AN XY: 713832

African (AFR) AF: 0.00 AC: 0 AN: 33062

American (AMR) AF: 0.00 AC: 0 AN: 42278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25644

East Asian (EAS) AF: 0.00 AC: 0 AN: 38692

South Asian (SAS) AF: 0.00 AC: 0 AN: 83232

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50342

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5616

European-Non Finnish (NFE) AF: 0.0000173 AC: 19 AN: 1101078

Other (OTH) AF: 0.00 AC: 0 AN: 59376

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152284 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74400

African (AFR) AF: 0.0000241 AC: 1 AN: 41478

American (AMR) AF: 0.00 AC: 0 AN: 15294

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5200

South Asian (SAS) AF: 0.00 AC: 0 AN: 4838

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10632

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68048

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis 2 Benign:3

Nov 07, 2021

Genome-Nilou Lab

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Oct 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

May 16, 2025

Myriad Genetics, Inc.

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered benign. This variant is a silent/synonymous amino acid change and it is not expected to impact splicing.

Tuberous sclerosis syndrome Uncertain:1 Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.

Aug 06, 2024

All of Us Research Program, National Institutes of Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Hereditary cancer-predisposing syndrome Benign:1

May 01, 2022

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 v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.45
CADD	Benign	4.8
DANN	Benign	0.90
PhyloP100		2.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs1167258871; hg19: chr16-2121915;