NM_000548.5:c.3914C>G

Variant names:

• chr16-2083725-C-G
• rs45517320
• NM_000548.5:c.3914C>G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM2 PM5 BP4_Moderate

The NM_000548.5(TSC2):​c.3914C>G​(p.Pro1305Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000692 in 1,445,382 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1305L) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.288

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
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-2083724-C-T is described in Lovd as [Pathogenic].
• BP4: Computational evidence support a benign effect (MetaRNN=0.14991552).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.3914C>G	p.Pro1305Arg	missense_variant	Exon 33 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.3914C>G	p.Pro1305Arg	missense_variant	Exon 33 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD3 exomes AF: 0.00000449 AC: 1 AN: 222830 Hom.: 0 AF XY: 0.00000832 AC XY: 1 AN XY: 120176

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000599

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: 6.92e-7 AC: 1 AN: 1445382 Hom.: 0 Cov.: 32 AF XY: 0.00000139 AC XY: 1 AN XY: 717292

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.05e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 34

ExAC AF: 0.00000831 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:1

Jul 28, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with TSC2-related disease. This variant is present in population databases (rs45517320, ExAC 0.02%). This sequence change replaces proline with arginine at codon 1305 of the TSC2 protein (p.Pro1305Arg). The proline residue is weakly conserved and there is a moderate physicochemical difference between proline and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.074
BayesDel_addAF	Uncertain	0.019	T
BayesDel_noAF	Uncertain	-0.030
CADD	Benign	17
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.48	T;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Benign	-0.84
Eigen_PC	Benign	-0.96
FATHMM_MKL	Benign	0.13	N
LIST_S2	Benign	0.79	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
M_CAP	Pathogenic	0.40	D
MetaRNN	Benign	0.15	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.32	T
MutationAssessor	Benign	0.69	N;.;.;.;.;.;.;.;.;.;.;.;.;.;.
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-1.9	N;.;.;N;.;N;.;.;N;N;.;.;.;.;N
REVEL	Uncertain	0.56
Sift	Benign	0.17	T;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Sift4G	Benign	0.59	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		1.0	D;.;.;.;B;B;.;.;B;B;.;.;.;.;.
Vest4		0.20
MutPred		0.32		Gain of solvent accessibility (P = 0.0216);.;.;.;.;.;.;Gain of solvent accessibility (P = 0.0216);.;.;.;.;.;.;.;
MVP		0.90
ClinPred		0.063	T
GERP RS		-0.89
Varity_R		0.061
gMVP		0.29

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs45517320; hg19: chr16-2133726;