rs1554820662

Positions:

• chr9-132927277-A-G
• chr9-132927277-A-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PP2 PP3_Strong PP5

The NM_000368.5(TSC1):​c.134T>C​(p.Leu45Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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. L45F) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:2
• Conservation: PhyloP100: 9.02

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 Pathogenic. Variant got 10 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 6 benign, 10 uncertain in NM_000368.5
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TSC1. . Gene score misZ 2.3217 (greater than the threshold 3.09). Trascript score misZ 3.6986 (greater than threshold 3.09). GenCC has associacion of gene with lung lymphangioleiomyomatosis, tuberous sclerosis 1, tuberous sclerosis, tuberous sclerosis complex, lymphangioleiomyomatosis.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.964
• PP5: Variant 9-132927277-A-G is Pathogenic according to our data. Variant chr9-132927277-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 534442.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Uncertain_significance=2}. Variant chr9-132927277-A-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TSC1	NM_000368.5	c.134T>C	p.Leu45Ser	missense_variant	4/23	ENST00000298552.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TSC1	ENST00000298552.9	c.134T>C	p.Leu45Ser	missense_variant	4/23	1	NM_000368.5	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tuberous sclerosis 1 Pathogenic:2 Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Laboratory of Medical Genetics, National & Kapodistrian University of Athens	Oct 01, 2021	PM2, PP1, PP3, PP4, PP5 -
Likely pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 24, 2022	In 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. 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 TSC1 protein function. ClinVar contains an entry for this variant (Variation ID: 534442). This missense change has been observed in individual(s) with clinical features of tuberous sclerosis complex (PMID: 30182498). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 45 of the TSC1 protein (p.Leu45Ser). -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Jul 01, 2023

TSC1: PM2, PM6, PS4:Supporting -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D;.;D;.;D;.;D;.;.;.;.;.;.;.;.;.;.;D;.;.;.
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Benign	0.82	.;T;D;D;.;.;.;D;D;.;T;.;.;D;D;D;T;D;D;D;D
M_CAP	Pathogenic	0.64	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Uncertain	2.5	M;M;M;.;M;.;M;.;.;M;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.66	T
PROVEAN	Uncertain	-4.4	D;D;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;.;.;.
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;.;.;.
Sift4G	Pathogenic	0.0	D;D;D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;.;.;.
Polyphen		1.0	D;.;D;.;D;.;D;.;.;.;.;D;D;D;.;.;.;D;.;.;.
Vest4		0.98
MutPred		0.84		Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);Gain of sheet (P = 0.0043);
MVP		0.97
MPC		1.7
ClinPred		1.0	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.79
gMVP		0.85

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: rs1554820662; hg19: chr9-135802664;