Genetic Information

Gene & Transcript Details

Gene
TSC2
Transcript
NM_000548.5 MANE Select
Total Exons
Reference Sequence
NC_000016.9
Alternative Transcripts
IDStatusDetails
NM_000548.3 Alternative 5675 nt | 107–5530
NM_000548.2 Alternative 5543 nt | 19–5442
NM_000548.4 Alternative 5751 nt | 201–5624
NM_000548.5 MANE Select 6415 nt | 111–5534

Variant Details

HGVS Notation
NM_000548.5:c.1653C>T
Protein Change
A551=
Location
Exon 16 (Exon 16 of )
16
5'Exon Structure3'
Functional Consequence
Loss of Function
Alternate Identifiers

Clinical & Population Data

Population Frequency

gnomAD
Global Frequency
0.00319 in 100,000
Extremely Rare
ACMG Criteria Applied PM2
This variant is absent or extremely rare in population databases (PM2 criteria applies).

ClinVar

Open
Classification
Likely Benign
3 publications
Clinical Statement

"This variant has been reported in ClinVar as Likely benign (4 clinical laboratories) and as Benign (2 clinical laboratories) and as Likely Benign (1 clinical laboratories)."

COSMIC Somatic Evidence

Open
COSMIC ID
Recurrence
0 occurrences
PM1 Criteria
Not Applied
COSMIC Database Preview
COSMIC Preview
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Functional Impact & Domains

Functional Domain

Hotspot Status
Not a hotspot
Domain Summary
This variant is not located in a mutational hotspot or critical domain.
Related Variants in This Domain
No evidence of other pathogenic variants at this position in gene TSC2.

Functional Studies & Therapeutic Relevance

Functional Summary

The variant has not been functionally characterized.

Database Previews
OncoKB
OncoKB Preview
JAX-CKB
JAX-CKB Preview

Click on previews to view full database entries. External databases may require institutional access.

Computational Analysis

Pathogenicity Predictions

SpliceAI
Predictor Consensus
Mixed/VUS
PP3 Applied
No
REVEL Score
0.0
Threshold: ≥0.75 = PP3 applied

SpliceAI Scores

Window: ±500bp
Effect Type Score Position
- Acceptor Loss (AL) 0.0 300 bp
- Donor Loss (DL) 0.0 63 bp
+ Acceptor Gain (AG) 0.0 205 bp
+ Donor Gain (DG) 0.0 -79 bp
High impact (≥0.5) Medium impact (0.2-0.49) Low impact (<0.2)

VCEP Guidelines

Applied ACMG/AMP Criteria (VCEP Specific)

Filter Criteria:
PVS1

PVS1 (Not Applied)

According to standard ACMG guidelines, the rule for PVS1 is: "Null variant in a gene where loss of function (LoF) is a known mechanism of disease (e.g., nonsense, frameshift, canonical ±1 or 2 splice sites, initiation codon, single exon deletion in a LoF gene)". The evidence for this variant shows: it is a synonymous change (c.1653C>T, p.A551=) and does not introduce a null allele. Therefore, this criterion is not applied because the variant type does not meet a null variant definition.

PS1

PS1 (Not Applied)

According to standard ACMG guidelines, the rule for PS1 is: "Same amino acid change as a known pathogenic variant but different nucleotide change". The evidence for this variant shows: no amino acid change (synonymous). Therefore, this criterion is not applied because there is no altered amino acid residue.

PS2

PS2 (Not Applied)

According to standard ACMG guidelines, the rule for PS2 is: "De novo (both maternity and paternity confirmed) in a patient with the disease and no family history". The evidence for this variant shows: no data on de novo occurrence. Therefore, this criterion is not applied due to lack of de novo evidence.

PS3

PS3 (Not Applied)

According to standard ACMG guidelines, the rule for PS3 is: "Well-established functional studies supportive of a damaging effect on the gene or gene product". The evidence for this variant shows: no functional studies have been performed. Therefore, this criterion is not applied because functional data are not available.

PS4

PS4 (Not Applied)

According to standard ACMG guidelines, the rule for PS4 is: "Prevalence in affected individuals significantly increased compared with controls". The evidence for this variant shows: no case-control or cohort data are available. Therefore, this criterion is not applied due to lack of prevalence data.

PM1

PM1 (Not Applied)

According to standard ACMG guidelines, the rule for PM1 is: "Located in a mutational hot spot or well-established functional domain without benign variation". The evidence for this variant shows: no indication that c.1653C>T lies in a known hotspot or critical domain. Therefore, this criterion is not applied.

PM2

PM2 (Moderate)

According to standard ACMG guidelines, the rule for PM2 is: "Absent from controls (or at extremely low frequency if recessive) (Table 6) in Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium". The evidence for this variant shows: MAF = 0.00319% in gnomAD with no homozygotes, which is well below disease thresholds. Therefore, this criterion is applied at Moderate strength because the variant is extremely rare in population databases.

PM3

PM3 (Not Applied)

According to standard ACMG guidelines, the rule for PM3 is: "Detected in trans with a pathogenic variant for recessive disorders". The evidence for this variant shows: no data on trans occurrence with a pathogenic allele. Therefore, this criterion is not applied.

PM4

PM4 (Not Applied)

According to standard ACMG guidelines, the rule for PM4 is: "Protein length changes due to in-frame deletions/insertions or stop-loss variants". The evidence for this variant shows: it is a synonymous change with no effect on protein length. Therefore, this criterion is not applied.

PM5

PM5 (Not Applied)

According to standard ACMG guidelines, the rule for PM5 is: "Novel missense change at an amino acid residue where a different pathogenic missense change has been seen". The evidence for this variant shows: it is not a missense variant. Therefore, this criterion is not applied.

PM6

PM6 (Not Applied)

According to standard ACMG guidelines, the rule for PM6 is: "Assumed de novo, but without confirmation of paternity and maternity". The evidence for this variant shows: no data on de novo status. Therefore, this criterion is not applied.

PP1

PP1 (Not Applied)

According to standard ACMG guidelines, the rule for PP1 is: "Co-segregation with disease in multiple affected family members". The evidence for this variant shows: no family segregation data. Therefore, this criterion is not applied.

PP2

PP2 (Not Applied)

According to standard ACMG guidelines, the rule for PP2 is: "Missense variant in a gene with a low rate of benign missense variation and where missense variants are a common mechanism of disease". The evidence for this variant shows: it is synonymous, not missense. Therefore, this criterion is not applied.

PP3

PP3 (Not Applied)

According to standard ACMG guidelines, the rule for PP3 is: "Multiple lines of computational evidence support a deleterious effect on the gene/gene product". The evidence for this variant shows: in silico tools are mixed or benign (CADD -0.51, SpliceAI = 0). Therefore, this criterion is not applied because computational evidence does not support pathogenicity.

PP4

PP4 (Not Applied)

According to standard ACMG guidelines, the rule for PP4 is: "Patient's phenotype or family history highly specific for a disease with a single genetic etiology". The evidence for this variant shows: no clinical phenotype data provided. Therefore, this criterion is not applied.

PP5

PP5 (Not Applied)

According to standard ACMG guidelines, the rule for PP5 is: "Reputable source reports variant as pathogenic, but without accessible evidence". The evidence for this variant shows: no reputable source reporting pathogenicity. Therefore, this criterion is not applied.

BA1

BA1 (Not Applied)

According to standard ACMG guidelines, the rule for BA1 is: "Allele frequency is too high for the disorder (based on population data)". The evidence for this variant shows: MAF = 0.00319%, which is below any BA1 threshold. Therefore, this criterion is not applied.

BS1

BS1 (Not Applied)

According to standard ACMG guidelines, the rule for BS1 is: "Allele frequency is greater than expected for the disorder". The evidence for this variant shows: frequency is very low. Therefore, this criterion is not applied.

BS2

BS2 (Not Applied)

According to standard ACMG guidelines, the rule for BS2 is: "Observed in healthy individuals with full penetrance expected at an early age". The evidence for this variant shows: no data on healthy adult observations. Therefore, this criterion is not applied.

BS3

BS3 (Not Applied)

According to standard ACMG guidelines, the rule for BS3 is: "Well-established functional studies show no damaging effect on protein function or splicing". The evidence for this variant shows: no functional assays performed. Therefore, this criterion is not applied.

BS4

BS4 (Not Applied)

According to standard ACMG guidelines, the rule for BS4 is: "Lack of segregation in affected family members". The evidence for this variant shows: no segregation data. Therefore, this criterion is not applied.

BP1

BP1 (Not Applied)

According to standard ACMG guidelines, the rule for BP1 is: "Missense variant in a gene where only loss of function causes disease". The evidence for this variant shows: it is synonymous. Therefore, this criterion is not applied.

BP2

BP2 (Not Applied)

According to standard ACMG guidelines, the rule for BP2 is: "Observed in trans with a pathogenic variant for dominant disorders or in cis with a pathogenic variant". The evidence for this variant shows: no phase data. Therefore, this criterion is not applied.

BP3

BP3 (Not Applied)

According to standard ACMG guidelines, the rule for BP3 is: "In-frame deletions/insertions in a repetitive region without known function". The evidence for this variant shows: not an indel. Therefore, this criterion is not applied.

BP4

BP4 (Supporting)

According to standard ACMG guidelines, the rule for BP4 is: "Multiple lines of computational evidence suggest no impact on gene or gene product (conservation, evolutionary, splicing impact, etc.)". The evidence for this variant shows: SpliceAI predicts no impact on splicing, CADD score is benign, and other in silico tools do not predict a deleterious effect. Therefore, this criterion is applied at Supporting strength because computational data support no functional impact.

BP5

BP5 (Not Applied)

According to standard ACMG guidelines, the rule for BP5 is: "Variant found in a case with an alternate molecular basis for disease". The evidence for this variant shows: no case reports with alternative diagnoses. Therefore, this criterion is not applied.

BP6

BP6 (Supporting)

According to standard ACMG guidelines, the rule for BP6 is: "Reputable source reports variant as benign, but without accessible evidence". The evidence for this variant shows: ClinVar entries from multiple laboratories classify it as Benign or Likely Benign without detailed evidence. Therefore, this criterion is applied at Supporting strength because of reputable source reports.

BP7

BP7 (Supporting)

According to standard ACMG guidelines, the rule for BP7 is: "Synonymous variant with no predicted impact on splicing". The evidence for this variant shows: c.1653C>T is synonymous and SpliceAI score = 0 for splice site creation or loss. Therefore, this criterion is applied at Supporting strength because it is a synonymous change with no splicing impact.