rs148756522

chr9-132912376-A-Cchr9-132912376-A-G

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 1P and 2B. PP2 BP4_Moderate

The NM_000368.5(TSC1):c.819T>G(p.Asp273Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000173 in 1,614,226 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 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. D273V) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000017 (0 hom.)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1
• Conservation: PhyloP100: -0.133

Genes affected

TSC1 (HGNC:12362): (TSC complex subunit 1) This gene is a tumor suppressor gene that encodes the growth inhibitory protein hamartin. The encoded protein interacts with and stabilizes the GTPase activating protein tuberin. This hamartin-tuberin complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. This protein also functions as a co-chaperone for Hsp90 that inhibits its ATPase activity. This protein functions as a facilitator of Hsp90-mediated folding of kinase and non-kinase clients, including TSC2 and thereby preventing their ubiquitination and proteasomal degradation. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]

ACMG classification

Verdict is Likely_benign. Variant got -1 ACMG points.

• PP2: Missense variant where missense usually causes diseases, TSC1
• BP4: Computational evidence support a benign effect (MetaRNN=0.09855348).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TSC1	NM_000368.5	c.819T>G	p.Asp273Glu	missense_variant	9/23	ENST00000298552.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TSC1	ENST00000298552.9	c.819T>G	p.Asp273Glu	missense_variant	9/23	1	NM_000368.5	P4

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152216 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000385

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251436 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135894

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

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: 0.0000171 AC: 25 AN: 1461892 Hom.: 0 Cov.: 31 AF XY: 0.0000124 AC XY: 9 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000101

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000171

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152334 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74502

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000386

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000151

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000824 AC: 1

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis 1 Uncertain:2 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Invitae	Jan 02, 2024	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Tuberous sclerosis syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Aug 08, 2023

This missense variant replaces aspartic acid with glutamic acid at codon 273 of the TSC1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with TSC1-related disorders in the literature. This variant has been identified in 1/251436 chromosomes 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. -

Isolated focal cortical dysplasia type II Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 07, 2023

The p.D273E variant (also known as c.819T>G), located in coding exon 7 of the TSC1 gene, results from a T to G substitution at nucleotide position 819. The aspartic acid at codon 273 is replaced by glutamic acid, an amino acid with highly 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Benign	-0.047	T
BayesDel_noAF	Benign	-0.31
Cadd	Benign	1.1
Dann	Benign	0.97
DEOGEN2	Benign	0.40	T;.;T;.;T;.;T;.;.;.;.;.;.;.;.;.;.;T;.
Eigen	Benign	-0.60
Eigen_PC	Benign	-0.51
FATHMM_MKL	Benign	0.39	N
M_CAP	Benign	0.027	D
MetaRNN	Benign	0.099	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.65	T
MutationAssessor	Benign	1.3	L;.;L;.;L;.;L;.;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	0.96	D;D;D;D;D
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	0.30	N;N;N;.;.;.;.;.;.;.;.;.;.;.;.;.;.;N;.
REVEL	Benign	0.23
Sift	Benign	0.58	T;T;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.
Sift4G	Benign	1.0	T;T;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.
Polyphen		0.048	B;.;B;.;B;.;B;.;.;.;.;P;P;P;.;.;.;B;.
Vest4		0.15
MutPred		0.63		Gain of disorder (P = 0.1433);.;Gain of disorder (P = 0.1433);Gain of disorder (P = 0.1433);Gain of disorder (P = 0.1433);Gain of disorder (P = 0.1433);Gain of disorder (P = 0.1433);Gain of disorder (P = 0.1433);Gain of disorder (P = 0.1433);.;.;Gain of disorder (P = 0.1433);Gain of disorder (P = 0.1433);Gain of disorder (P = 0.1433);Gain of disorder (P = 0.1433);Gain of disorder (P = 0.1433);.;Gain of disorder (P = 0.1433);.;
MVP		0.65
MPC		0.93
ClinPred		0.23	T
GERP RS		0.80
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.047
gMVP		0.15

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs148756522; hg19: chr9-135787763;