16-2064309-C-T

Position:

• chr16-2064309-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000548.5(TSC2):​c.1481C>T​(p.Ser494Phe) 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 1,461,560 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:1
• Conservation: PhyloP100: 3.54

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TSC2	NM_000548.5	c.1481C>T	p.Ser494Phe	missense_variant	15/42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.1481C>T	p.Ser494Phe	missense_variant	15/42	5	NM_000548.5	ENSP00000219476

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251366 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135876

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: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461560 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 727068

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1 Benign:1

Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 23, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 04, 2024

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; This variant is associated with the following publications: (PMID: 34580720) -

Isolated focal cortical dysplasia type II Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Jul 07, 2023

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 02, 2023

The p.S494F variant (also known as c.1481C>T), located in coding exon 14 of the TSC2 gene, results from a C to T substitution at nucleotide position 1481. The serine at codon 494 is replaced by phenylalanine, an amino acid with highly dissimilar properties. This amino acid position is not well 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	Benign	0.27
BayesDel_addAF	Uncertain	0.064	T
BayesDel_noAF	Uncertain	-0.050
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.88	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.91	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Benign	0.067	D
MetaRNN	Uncertain	0.55	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.28	T
MutationAssessor	Benign	1.4	L;.;.;.;L;L;.;.;.;L;.;L;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Benign	0.46	T
PROVEAN	Uncertain	-3.8	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Uncertain	0.33
Sift	Uncertain	0.0070	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Uncertain	0.0090	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen		0.90	P;.;.;.;P;P;.;.;P;B;.;.;.;.;.
Vest4		0.58
MutPred		0.50		Loss of disorder (P = 0.0047);Loss of disorder (P = 0.0047);Loss of disorder (P = 0.0047);.;Loss of disorder (P = 0.0047);Loss of disorder (P = 0.0047);Loss of disorder (P = 0.0047);Loss of disorder (P = 0.0047);.;Loss of disorder (P = 0.0047);Loss of disorder (P = 0.0047);Loss of disorder (P = 0.0047);Loss of disorder (P = 0.0047);Loss of disorder (P = 0.0047);.;
MVP		0.66
ClinPred		0.96	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.32
gMVP		0.42

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

Publications

LitVar

Other links and lift over

dbSNP: rs751984707; hg19: chr16-2114310;