9-132927244-G-A

Variant names:

• chr9-132927244-G-A
• rs750512029
• NM_000368.5:c.167C>T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM1 BP4 BP6 BS2

The NM_000368.5(TSC1):​c.167C>T​(p.Pro56Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000889 in 1,461,750 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 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. P56S) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000089 (0 hom.)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:3
• Conservation: PhyloP100: 5.50
• Publications: 2 publications found

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]

TSC1 Gene-Disease associations (from GenCC):

• tuberous sclerosis

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• tuberous sclerosis 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, PanelApp Australia, Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae)
• lung lymphangioleiomyomatosis

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• tuberous sclerosis complex

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 5 benign, 21 uncertain in NM_000368.5
• BP4: Computational evidence support a benign effect (MetaRNN=0.34630924).
• BP6: Variant 9-132927244-G-A is Benign according to our data. Variant chr9-132927244-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 388596.
• BS2: High AC in GnomAdExome4 at 13 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC1	NM_000368.5	c.167C>T	p.Pro56Leu	missense_variant	Exon 4 of 23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.167C>T	p.Pro56Leu	missense_variant	Exon 4 of 23	1	NM_000368.5	ENSP00000298552.3
TSC1	ENST00000490179.4	c.167C>T	p.Pro56Leu	missense_variant	Exon 5 of 24	3		ENSP00000495533.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000159 AC: 4 AN: 251352 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000889 AC: 13 AN: 1461750 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727170

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.0000447 AC: 2 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86224

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000989 AC: 11 AN: 1111932

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000165 AC: 2

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis 1 Benign:2

Dec 09, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 07, 2021

Genome-Nilou Lab

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Uncertain:1

Aug 15, 2016

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

A variant of uncertain significance has been identified in the TSC1 gene. The P56Lvariant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The P56L variant is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties. Missense variants in nearby residues (L61R, L61P) have been reported in the Human Gene Mutation Database in association with tuberous sclerosis. However, this substitution occurs at a position that is not conserved in species. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Hereditary cancer-predisposing syndrome Uncertain:1

Oct 10, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P56L variant (also known as c.167C>T), located in coding exon 2 of the TSC1 gene, results from a C to T substitution at nucleotide position 167. The proline at codon 56 is replaced by leucine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. 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 syndrome Benign:1

Mar 23, 2023

All of Us Research Program, National Institutes of Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.099
BayesDel_addAF	Benign	-0.055	T
BayesDel_noAF	Benign	-0.14
CADD	Benign	21
DANN	Benign	0.79
DEOGEN2	Uncertain	0.43	T;.;T;.;T;.;T;.;.;.;.;.;.;.;.;.;.;T;.;.;.
Eigen	Benign	0.044
Eigen_PC	Benign	0.051
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.93	.;D;D;D;.;.;.;D;D;.;D;.;.;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.13	D
MetaRNN	Benign	0.35	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.12	T
MutationAssessor	Benign	1.8	L;L;L;.;L;.;L;.;.;L;.;.;.;.;.;.;.;.;.;.;.
PhyloP100		5.5
PrimateAI	Benign	0.38	T
PROVEAN	Benign	-0.75	N;N;N;.;.;.;.;.;.;.;.;.;.;.;.;.;.;N;.;.;.
REVEL	Uncertain	0.38
Sift	Benign	0.093	T;T;T;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.;.
Sift4G	Uncertain	0.045	D;D;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;T;.;.;.
Polyphen		0.042	B;.;B;.;B;.;B;.;.;.;.;P;P;P;.;.;.;P;.;.;.
Vest4		0.47
MutPred		0.58		Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);Loss of loop (P = 0.0073);
MVP		0.52
MPC		0.64
ClinPred		0.22	T
GERP RS		3.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.047
gMVP		0.28
Mutation Taster		=65/35	polymorphism

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

Other links and lift over

dbSNP: rs750512029; hg19: chr9-135802631; COSMIC: COSV107323240; COSMIC: COSV107323240;