rs1555440475

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_000548.5(TSC2):ā€‹c.5177A>Cā€‹(p.His1726Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,728 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (ā˜…ā˜…). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H1726Y) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)
Exomes š‘“: 6.8e-7 ( 0 hom. )

Consequence

TSC2
NM_000548.5 missense

Scores

10
6
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 9.16
Variant links:
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 17 uncertain in NM_000548.5
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.909

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
TSC2NM_000548.5 linkuse as main transcriptc.5177A>C p.His1726Pro missense_variant 41/42 ENST00000219476.9

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TSC2ENST00000219476.9 linkuse as main transcriptc.5177A>C p.His1726Pro missense_variant 41/425 NM_000548.5 P49815-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
6.85e-7
AC:
1
AN:
1460728
Hom.:
0
Cov.:
35
AF XY:
0.00
AC XY:
0
AN XY:
726642
show subpopulations
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:
0.00
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.0000468
Hom.:
0

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Tuberous sclerosis 2 Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingGenome-Nilou LabNov 07, 2021- -
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpSep 12, 2023In 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. This sequence change replaces histidine, which is basic and polar, with proline, which is neutral and non-polar, at codon 1726 of the TSC2 protein (p.His1726Pro). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TSC2-related conditions. ClinVar contains an entry for this variant (Variation ID: 468144). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt TSC2 protein function. -
Tuberous sclerosis syndrome Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAll of Us Research Program, National Institutes of HealthNov 30, 2023This missense variant replaces histidine with proline at codon 1726 of the TSC2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with h tuberous sclerosis complex (TSC) in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingGeneDxFeb 02, 2024Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in an individual with unspecified features of tuberous sclerosis complex (PMID: 37356622); This variant is associated with the following publications: (PMID: 37356622) -
TSC2-related disorder Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingPreventionGenetics, part of Exact SciencesNov 03, 2022The TSC2 c.5177A>C variant is predicted to result in the amino acid substitution p.His1726Pro. To our knowledge, this variant has not been reported in the literature or in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Isolated focal cortical dysplasia type II Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingBaylor GeneticsNov 12, 2023- -
Hereditary cancer-predisposing syndrome Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsFeb 13, 2024The p.H1726P variant (also known as c.5177A>C), located in coding exon 40 of the TSC2 gene, results from an A to C substitution at nucleotide position 5177. The histidine at codon 1726 is replaced by proline, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.95
BayesDel_addAF
Pathogenic
0.47
D
BayesDel_noAF
Pathogenic
0.44
CADD
Uncertain
25
DANN
Benign
0.96
DEOGEN2
Pathogenic
0.93
D;.;.;.;.;.;.;.;.;.;.;.;D;.;D
Eigen
Uncertain
0.54
Eigen_PC
Uncertain
0.48
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.95
D;D;D;D;D;D;D;D;D;D;D;D;D;T;D
M_CAP
Pathogenic
0.67
D
MetaRNN
Pathogenic
0.91
D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
0.81
D
MutationAssessor
Uncertain
2.1
M;.;.;.;.;.;.;.;.;.;.;.;.;.;.
MutationTaster
Benign
1.0
D;D;D;D;D;D;D
PrimateAI
Uncertain
0.67
T
PROVEAN
Pathogenic
-4.5
D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
REVEL
Pathogenic
0.91
Sift
Benign
0.095
T;.;.;T;.;T;.;.;T;T;.;.;.;.;T
Sift4G
Uncertain
0.026
D;.;.;D;.;D;.;.;D;D;.;.;.;.;D
Polyphen
1.0
D;.;.;.;D;D;.;.;D;D;.;.;.;.;.
Vest4
0.89
MutPred
0.70
Loss of helix (P = 0.0068);.;.;.;.;.;.;.;.;.;.;.;.;.;.;
MVP
0.97
ClinPred
0.98
D
GERP RS
4.2
Varity_R
0.96
gMVP
0.87

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs1555440475; hg19: chr16-2138244; API