rs750512029

chr9-132927244-G-Achr9-132927244-G-C

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 1P and 2B. PP2 BP4 BP6

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. 13/21 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. 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

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=0.34630924).
• 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 id is 388596.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=2, Likely_benign=2, Benign=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TSC1	NM_000368.5	c.167C>T	p.Pro56Leu	missense_variant	4/23	ENST00000298552.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TSC1	ENST00000298552.9	c.167C>T	p.Pro56Leu	missense_variant	4/23	1	NM_000368.5	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251352 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135856

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 SAS exome AF: 0.0000327

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

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

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: 0.00000989

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

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

Benign, criteria provided, single submitter	clinical testing	Invitae	Feb 01, 2024	- -
Likely benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Aug 15, 2016

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 10, 2023

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

Likely benign, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Mar 23, 2023

- -

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
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;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D
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

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: rs750512029; hg19: chr9-135802631;