NM_000548.5:c.1417C>T

Variant names:

• chr16-2063027-C-T
• rs1321215329
• NM_000548.5:c.1417C>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Moderate BP6 BP7

The NM_000548.5(TSC2):​c.1417C>T​(p.Leu473Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. L473L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TSC2 NM_000548.5 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 2.95
• Publications: 0 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 -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.34).
• BP6: Variant 16-2063027-C-T is Benign according to our data. Variant chr16-2063027-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1103056.
• BP7: Synonymous conserved (PhyloP=2.95 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.1417C>T	p.Leu473Leu	synonymous_variant	Exon 14 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.1417C>T	p.Leu473Leu	synonymous_variant	Exon 14 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1399208 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 690130

African (AFR) AF: 0.00 AC: 0 AN: 31594

American (AMR) AF: 0.00 AC: 0 AN: 35704

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25172

East Asian (EAS) AF: 0.00 AC: 0 AN: 35734

South Asian (SAS) AF: 0.00 AC: 0 AN: 79236

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49178

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5690

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1078910

Other (OTH) AF: 0.00 AC: 0 AN: 57990

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Jan 27, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1417C>T variant (also known as p.L473L), located in coding exon 13 of the TSC2 gene, results from a C to T substitution at nucleotide position 1417. This nucleotide substitution does not change the amino acid at codon 473. This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Tuberous sclerosis 2 Benign:1

Oct 22, 2023

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
BayesDel_noAF	Benign	-0.34
CADD	Benign	15
DANN	Benign	0.74
PhyloP100		2.9
PromoterAI		0.0044	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.13		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: rs1321215329; hg19: chr16-2113028;