16-2084346-C-T

Variant names:

• chr16-2084346-C-T
• rs145476528
• NM_000548.5:c.4124C>T

Variant summary

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

The NM_000548.5(TSC2):​c.4124C>T​(p.Ser1375Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,236 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: 𝑓 0.0000066 (0 hom., cov: 34)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:1
• Conservation: PhyloP100: 7.24

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 rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.4124C>T	p.Ser1375Phe	missense_variant	Exon 34 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.4124C>T	p.Ser1375Phe	missense_variant	Exon 34 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152236 Hom.: 0 Cov.: 34

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000402 AC: 1 AN: 248980 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135286

Gnomad AFR exome AF: 0.0000623

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152236 Hom.: 0 Cov.: 34 AF XY: 0.0000134 AC XY: 1 AN XY: 74360

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ESP6500AA AF: 0.000228 AC: 1

ESP6500EA AF: 0.00 AC: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Lymphangiomyomatosis;C1846385:Isolated focal cortical dysplasia type II;C1860707:Tuberous sclerosis 2 Uncertain:1

Feb 08, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

TSC2-related disorder Uncertain:1

Oct 11, 2023

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The TSC2 c.4124C>T variant is predicted to result in the amino acid substitution p.Ser1375Phe. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0062% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/16-2134347-C-T). It has conflicting interpretations of benign and uncertain significance in ClinVar (https://preview.ncbi.nlm.nih.gov/clinvar/variation/577422/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

not provided Uncertain:1

Nov 13, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 -

Hereditary cancer-predisposing syndrome Uncertain:1

Feb 20, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.S1375F variant (also known as c.4124C>T), located in coding exon 33 of the TSC2 gene, results from a C to T substitution at nucleotide position 4124. The serine at codon 1375 is replaced by phenylalanine, an amino acid with highly dissimilar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this alteration remains unclear. -

Tuberous sclerosis 2 Benign:1

Jan 03, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.75	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Uncertain	0.26
Eigen_PC	Uncertain	0.31
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.33	D
MetaRNN	Uncertain	0.68	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.14	D
MutationAssessor	Benign	1.9	L;.;.;.;.;.;.;.;.;.;.;.;.;.;.
PrimateAI	Benign	0.39	T
PROVEAN	Benign	-2.3	N;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Uncertain	0.54
Sift	Uncertain	0.0020	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Uncertain	0.023	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen		0.92	P;.;.;.;P;P;.;.;P;P;.;.;.;.;.
Vest4		0.45
MVP		0.87
ClinPred		0.92	D
GERP RS		4.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.16
gMVP		0.41

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs145476528; hg19: chr16-2134347;