9-132907302-T-G

Variant names:

• chr9-132907302-T-G
• rs773003016
• NM_000368.5:c.1332A>C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM2 PP3 BP6

The NM_000368.5(TSC1):​c.1332A>C​(p.Ser444Ser) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,160 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. S444S) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TSC1 NM_000368.5 splice_region, synonymous
• Scores: Splicing: ADA: 0.9944
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:2
• Conservation: PhyloP100: 1.51
• 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: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• BP6: Variant 9-132907302-T-G is Benign according to our data. Variant chr9-132907302-T-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 534462.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TSC1	NM_000368.5	c.1332A>C	p.Ser444Ser	splice_region_variant, synonymous_variant	Exon 13 of 23	ENST00000298552.9	NP_000359.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TSC1	ENST00000298552.9	c.1332A>C	p.Ser444Ser	splice_region_variant, synonymous_variant	Exon 13 of 23	1	NM_000368.5	ENSP00000298552.3
TSC1	ENST00000490179.4	c.1332A>C	p.Ser444Ser	splice_region_variant, synonymous_variant	Exon 14 of 24	3		ENSP00000495533.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461160 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 726922

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

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86248

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111362

Other (OTH) AF: 0.00 AC: 0 AN: 60366

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000371 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis 1 Uncertain:1 Benign:1

Jan 12, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nov 07, 2021

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Tuberous sclerosis syndrome Uncertain:1

Jun 26, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This synonymous variant causes a nucleotide substitution but does not change the encoded amino acid at codon 444 of the TSC1 protein. Splice site prediction tools suggest that this variant may impact RNA splicing. 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 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

Aug 15, 2019

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes splice predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge

Hereditary cancer-predisposing syndrome Benign:1

Oct 12, 2023

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.33
CADD	Benign	16
DANN	Benign	0.89
PhyloP100		1.5
PromoterAI		-0.067	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.89
SpliceAI score (max)		0.020		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: rs773003016; hg19: chr9-135782689;