NM_000368.5:c.236A>G

Variant names:

• chr9-132925714-T-C
• rs373855276
• NM_000368.5:c.236A>G

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_000368.5(TSC1):​c.236A>G​(p.Tyr79Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 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. Y79H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TSC1 NM_000368.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 4.53
• 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: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics, Genomics England PanelApp
• 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 -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.17723975).
• BP6: Variant 9-132925714-T-C is Benign according to our data. Variant chr9-132925714-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 466075.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000368.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TSC1	NM_000368.5	MANE Select	c.236A>G	p.Tyr79Cys	missense	Exon 5 of 23	NP_000359.1	Q92574-1
	TSC1	NM_001362177.2		c.-128A>G		5_prime_UTR_premature_start_codon_gain	Exon 4 of 22	NP_001349106.1	A0A2R8Y5M3
	TSC1	NM_001406614.1		c.-220A>G		5_prime_UTR_premature_start_codon_gain	Exon 4 of 23	NP_001393543.1	A0A2R8Y5M3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TSC1	ENST00000298552.9	TSL:1 MANE Select	c.236A>G	p.Tyr79Cys	missense	Exon 5 of 23	ENSP00000298552.3	Q92574-1
	TSC1	ENST00000490179.4	TSL:3	c.236A>G	p.Tyr79Cys	missense	Exon 6 of 24	ENSP00000495533.2	Q92574-1
	TSC1	ENST00000403810.6	TSL:1	c.236A>G	p.Tyr79Cys	missense	Exon 5 of 10	ENSP00000386093.1	Q86WV8

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461888 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727244

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112008

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	-	1	Hereditary cancer-predisposing syndrome (1)
-	1	-	Tuberous sclerosis 1 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.095	T
BayesDel_noAF	Benign	-0.37
CADD	Benign	18
DANN	Uncertain	0.98
DEOGEN2	Benign	0.40	T
Eigen	Benign	-0.30
Eigen_PC	Benign	-0.11
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Uncertain	0.89	D
M_CAP	Benign	0.011	T
MetaRNN	Benign	0.18	T
MetaSVM	Benign	-0.99	T
MutationAssessor	Benign	0.68	N
PhyloP100		4.5
PrimateAI	Benign	0.37	T
PROVEAN	Benign	1.2	N
REVEL	Benign	0.058
Sift	Benign	0.63	T
Sift4G	Benign	0.43	T
Polyphen		0.0	B
Vest4		0.38
MVP		0.21
MPC		0.64
ClinPred		0.45	T
GERP RS		4.2
Varity_R		0.061
gMVP		0.68
Mutation Taster		=75/25	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
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: rs373855276; hg19: chr9-135801101; COSMIC: COSV53776175;