16-2054334-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000548.5(TSC2):c.375G>C(p.Lys125Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,614,068 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 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. K125R) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 0.667

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.16971156).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TSC2	NM_000548.5	c.375G>C	p.Lys125Asn	missense_variant	5/42	ENST00000219476.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TSC2	ENST00000219476.9	c.375G>C	p.Lys125Asn	missense_variant	5/42	5	NM_000548.5

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152184 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

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251484 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135920

Gnomad AFR exome AF: 0.0000615

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 AF: 0.00000205 AC: 3 AN: 1461884 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727248

Gnomad4 AFR exome AF: 0.0000597

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152184 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74346

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	curation	Sema4, Sema4	Mar 10, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Sep 11, 2023	The p.K125N variant (also known as c.375G>C), located in coding exon 4 of the TSC2 gene, results from a G to C substitution at nucleotide position 375. The lysine at codon 125 is replaced by asparagine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Tuberous sclerosis 2 Uncertain:1 Benign:1

Benign, criteria provided, single submitter	clinical testing	Invitae	Jun 27, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.21
Cadd	Benign	21
Dann	Uncertain	0.99
DEOGEN2	Uncertain	0.49	T;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-0.43
Eigen_PC	Benign	-0.34
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Benign	0.82	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Benign	0.084	D
MetaRNN	Benign	0.17	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.46	T
MutationAssessor	Benign	0.67	N;.;.;.;N;N;.;.;.;N;.;N;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-1.8	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Benign	0.27
Sift	Benign	0.31	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Uncertain	0.049	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen		1.0	D;.;.;.;.;B;.;.;B;B;.;.;.;.;.
Vest4		0.51
MutPred		0.46		Loss of methylation at K125 (P = 0.002);Loss of methylation at K125 (P = 0.002);Loss of methylation at K125 (P = 0.002);.;Loss of methylation at K125 (P = 0.002);Loss of methylation at K125 (P = 0.002);Loss of methylation at K125 (P = 0.002);Loss of methylation at K125 (P = 0.002);.;Loss of methylation at K125 (P = 0.002);Loss of methylation at K125 (P = 0.002);Loss of methylation at K125 (P = 0.002);Loss of methylation at K125 (P = 0.002);Loss of methylation at K125 (P = 0.002);.;
MVP		0.92
ClinPred		0.053	T
GERP RS		1.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.20
gMVP		0.45

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.11		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: rs778928295; hg19: chr16-2104335;