16-2054350-C-G

Variant names:

• chr16-2054350-C-G
• rs777398393
• NM_000548.5:c.391C>G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP6

The NM_000548.5(TSC2):​c.391C>G​(p.Pro131Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,890 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: 0.0000014 (0 hom.)
• Consequence: TSC2 NM_000548.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 7.78

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP6: Variant 16-2054350-C-G is Benign according to our data. Variant chr16-2054350-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 962260.We mark this variant Likely_benign, oryginal submissions are: {Benign=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC2	NM_000548.5	c.391C>G	p.Pro131Ala	missense_variant	Exon 5 of 42	ENST00000219476.9	NP_000539.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC2	ENST00000219476.9	c.391C>G	p.Pro131Ala	missense_variant	Exon 5 of 42	5	NM_000548.5	ENSP00000219476.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251484 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135920

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461890 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727248

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: 8.99e-7

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Isolated focal cortical dysplasia type II Uncertain:1

Jun 09, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Dec 24, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P131A variant (also known as c.391C>G), located in coding exon 4 of the TSC2 gene, results from a C to G substitution at nucleotide position 391. The proline at codon 131 is replaced by alanine, an amino acid with highly similar properties. This amino acid position is conserved. 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. -

Tuberous sclerosis 2 Benign:1

Dec 19, 2022

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	0.19
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.060
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.55	D;.;.;.;.;.;.;.;.;.;.;.;T;.;T
Eigen	Uncertain	0.30
Eigen_PC	Uncertain	0.27
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Uncertain	0.65	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.14	T
MutationAssessor	Uncertain	2.1	M;.;.;.;M;M;.;.;.;M;.;M;.;.;.
PrimateAI	Uncertain	0.64	T
PROVEAN	Uncertain	-2.7	D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL	Uncertain	0.58
Sift	Benign	0.20	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G	Benign	0.065	T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Polyphen		1.0	D;.;.;.;.;P;.;.;D;D;.;.;.;.;.
Vest4		0.69
MutPred		0.36		Loss of loop (P = 0.0075);Loss of loop (P = 0.0075);Loss of loop (P = 0.0075);.;Loss of loop (P = 0.0075);Loss of loop (P = 0.0075);Loss of loop (P = 0.0075);Loss of loop (P = 0.0075);.;Loss of loop (P = 0.0075);Loss of loop (P = 0.0075);Loss of loop (P = 0.0075);Loss of loop (P = 0.0075);Loss of loop (P = 0.0075);.;
MVP		0.66
ClinPred		0.81	D
GERP RS		4.0
Varity_R		0.18
gMVP		0.43

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs777398393; hg19: chr16-2104351;