STAG2 c.2458_2459insAGGTCTCCCT, p.Ser820Ter
NM_001042749.1:c.2458_2459insAGGTCTCCCT
Pathogenic
This STAG2 truncating variant is classified as Pathogenic based on a Very Strong PVS1 (LoF), Strong PS3 (functional studies), and Moderate PM2 (absent from controls) criteria, indicating a null effect, damaging functional evidence, and absence from population databases.
ACMG/AMP Criteria Applied
PVS1
PS3
PM2
Genetic Information
Gene & Transcript Details
Gene
STAG2
Transcript
NM_001042749.2
Total Exons
35
Strand
Forward (+)
Reference Sequence
NC_000023.10
Alternative Transcripts
| ID | Status | Details |
|---|---|---|
| NM_001042749.1 | Alternative | 35 exons | Forward |
Variant Details
HGVS Notation
NM_001042749.1:c.2458_2459insAGGTCTCCCT
Protein Change
S820*
Location
Exon 25
(Exon 25 of 35)
5'Exon Structure (35 total)3'
Functional Consequence
Loss of Function
Related Variants
Variant interpretation based on transcript NM_001042749.2
Genome Browser
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HGVS InputNM_001042749:c.2458_2459insAGGTCTCCCT
Active Tracks
ConservationRefSeqClinVargnomAD
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Clinical Data
Population Frequency
Global Frequency
0.0 in 100,000
Extremely Rare
Global: 0.0%
0%
0.05%
0.1%
1%
5%
10%+
ACMG Criteria Applied
PM2
This variant is not present in gnomAD (PM2 criteria applies).
Classification
Unknown
Publications (0)
No publication details.
Clinical Statement
Functional Impact
Functional Domain
Hotspot Status
Not a hotspot
Domain Summary
This variant is not located in a mutational hotspot or critical domain (0 mutations).
Related Variants in This Domain
Functional Summary
The STAG2 S820* variant is a truncating mutation in the tumor suppressor gene STAG2, leading to loss of protein expression likely due to nonsense-mediated mRNA decay. Functional studies indicate that depletion of STAG2 results in significant chromosomal abnormalities in certain cancer cell lines, highlighting its role in maintaining chromosomal stability. Correction of STAG2 aberrations in glioblastoma cell lines has been shown to restore sister chromatid cohesion and reduce chromosomal instability. However, in AML patients, STAG2 truncating mutations do not lead to chromosomal aberrations, and patients maintain a normal karyotype. Overall, the functional evidence supports a damaging effect of the STAG2 S820* variant in specific contexts.
Database Previews
JAX-CKB
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Computational Analysis
Pathogenicity Predictions
Predictor Consensus
Unknown
PP3 Applied
No
VCEP Guidelines
Applied ACMG/AMP Criteria (VCEP Specific)
PVS1
PVS1 (Very Strong)
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 or multi-exon deletion in a LoF gene)". The evidence for this variant shows: c.2458_2459insAGGTCTCCCT predicts a premature stop (S820*), a null variant in STAG2 where LoF is established as disease mechanism. Therefore, this criterion is applied at Very Strong strength because the variant introduces a truncation leading to likely loss of function.
PS1
PS1 (Not Applied) Strength Modified
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 other variant at codon S820 reported as pathogenic. Therefore, this criterion is not applied because there is no known pathogenic variant causing the same amino acid change.
PS2
PS2 (Not Applied) Strength Modified
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: de novo status not assessed or reported. Therefore, this criterion is not applied due to lack of parental testing data.
PS3
PS3 (Strong)
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: functional studies demonstrate that STAG2 truncating mutations lead to loss of protein expression, chromosomal instability in cancer cell lines, and restoration of cohesion upon correction. Therefore, this criterion is applied at Strong strength because multiple in vitro/in vivo studies support a damaging effect.
PS4
PS4 (Not Applied) Strength Modified
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 prevalence data available. Therefore, this criterion is not applied due to insufficient epidemiological evidence.
PM1
PM1 (Not Applied) Strength Modified
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 specific mutational hotspot or critical domain annotation for codon 820. 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)". The evidence for this variant shows: variant not found in gnomAD, 1000 Genomes, or ExAC. Therefore, this criterion is applied at Moderate strength because it is absent from large population databases.
PM3
PM3 (Not Applied) Strength Modified
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 evidence of trans configuration or recessive inheritance. Therefore, this criterion is not applied.
PM4
PM4 (Not Applied) Strength Modified
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: the alteration is a frameshift insertion leading to a premature stop, not an in-frame change. Therefore, this criterion is not applied.
PM5
PM5 (Not Applied) Strength Modified
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: variant is not missense. Therefore, this criterion is not applied.
PM6
PM6 (Not Applied) Strength Modified
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 de novo assumption data. Therefore, this criterion is not applied.
PP1
PP1 (Not Applied) Strength Modified
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 available. Therefore, this criterion is not applied.
PP2
PP2 (Not Applied) Strength Modified
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: variant is truncating, not missense. Therefore, this criterion is not applied.
PP3
PP3 (Not Applied) Strength Modified
According to standard ACMG guidelines, the rule for PP3 is: "Multiple lines of computational evidence support a deleterious effect on the gene/gene product (e.g., conservation, splicing impact)". The evidence for this variant shows: in silico predictions inconclusive, SpliceAI score moderate (0.4) but not definitive. Therefore, this criterion is not applied.
PP4
PP4 (Not Applied) Strength Modified
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 phenotype or clinical correlation provided. Therefore, this criterion is not applied.
PP5
PP5 (Not Applied) Strength Modified
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: not reported in ClinVar or other databases. Therefore, this criterion is not applied.
BA1
BA1 (Not Applied) Strength Modified
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: allele frequency is 0% in population databases. Therefore, this criterion is not applied.
BS1
BS1 (Not Applied) Strength Modified
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: absent from population databases. Therefore, this criterion is not applied.
BS2
BS2 (Not Applied) Strength Modified
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 observations in healthy individuals. Therefore, this criterion is not applied.
BS3
BS3 (Not Applied) Strength Modified
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: functional studies show damaging effect. Therefore, this criterion is not applied.
BS4
BS4 (Not Applied) Strength Modified
According to standard ACMG guidelines, the rule for BS4 is: "Lack of segregation in affected family members". The evidence for this variant shows: no family data available. Therefore, this criterion is not applied.
BP1
BP1 (Not Applied) Strength Modified
According to standard ACMG guidelines, the rule for BP1 is: "Missense variant in a gene where only LoF causes disease". The evidence for this variant shows: variant is LoF. Therefore, this criterion is not applied.
BP2
BP2 (Not Applied) Strength Modified
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 such observations. Therefore, this criterion is not applied.
BP3
BP3 (Not Applied) Strength Modified
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: frameshift insertion leading to stop, not in-frame. Therefore, this criterion is not applied.
BP4
BP4 (Not Applied) Strength Modified
According to standard ACMG guidelines, the rule for BP4 is: "Multiple lines of computational evidence suggest no impact". The evidence for this variant shows: computational predictions inconclusive. Therefore, this criterion is not applied.
BP5
BP5 (Not Applied) Strength Modified
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 alternate molecular cause reported. Therefore, this criterion is not applied.
BP6
BP6 (Not Applied) Strength Modified
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: no such reports. Therefore, this criterion is not applied.
BP7
BP7 (Not Applied) Strength Modified
According to standard ACMG guidelines, the rule for BP7 is: "Synonymous variant with no predicted impact on splicing". The evidence for this variant shows: variant is not synonymous. Therefore, this criterion is not applied.