CTNNB1 c.1004A>T, p.Lys335Ile
NM_001904.4:c.1004A>T
COSMIC ID: COSM17797
Likely Pathogenic
This variant is classified as Likely Pathogenic based on one strong functional criterion (PS3), two moderate criteria (PM1, PM2), and one benign supporting computational criterion (BP4) which does not outweigh the pathogenic evidence.
ACMG/AMP Criteria Applied
PS3
PM1
PM2
BP4
Genetic Information
Gene & Transcript Details
Gene
CTNNB1
Transcript
NM_001904.4
MANE Select
Total Exons
15
Strand
Forward (+)
Reference Sequence
NC_000003.11
Alternative Transcripts
| ID | Status | Details |
|---|---|---|
| NM_001904.3 | Alternative | 15 exons | Forward |
Variant Details
HGVS Notation
NM_001904.4:c.1004A>T
Protein Change
K335I
Location
Exon 7
(Exon 7 of 15)
5'Exon Structure (15 total)3'
Functional Consequence
Loss of Function
Related Variants
No evidence of other pathogenic variants at position 335 in gene CTNNB1
Alternate Identifiers
COSM17797
Variant interpretation based on transcript NM_001904.4
Genome Browser
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HGVS InputNM_001904:c.1004A>T
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
Not Classified
Publications (0)
No publication details.
Clinical Statement
Present in ClinVar, however no clinical evidence available for this variant.
COSMIC ID
COSM17797
Recurrence
55 occurrences
PM1 Criteria
Applied
Criterion PM1 is applied based on the high recurrence in COSMIC database.
COSMIC Database Preview
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Functional Impact
Functional Domain
Hotspot Status
Hotspot
PM1
Mutation Count
38
Reported mutations in this domain
050100+
Domain Summary
This variant is located in a mutational hotspot or critical domain (38 mutations).
PM1 criterion applied.
Related Variants in This Domain
No evidence of other pathogenic variants at position 335 in gene CTNNB1
Functional Summary
The CTNNB1 K335I variant has been functionally characterized and demonstrated to be oncogenic. It is located in the APC/Axin binding region of β-catenin and has been shown to increase protein activity and tumor growth in both cell lines and xenograft models. Although it exhibits phosphorylation and protein stability similar to the wild-type, it is weakly activating in cultured cells, enhancing CTNNB1 signaling activity and promoting tumor growth in mouse models.
Database Previews
OncoKB
JAX-CKB
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Computational Analysis
Pathogenicity Predictions
REVEL Score
0.62
0.62
Likely Benign0.0
Uncertain (Low)0.2
Uncertain (Med)0.5
Likely Pathogenic0.75
REVEL scores ≥ 0.75 are strong evidence (PP3)
Predictor Consensus
Mixed/VUS
PP3 Applied
No
Additional Predictors
Pathogenic:
polyphen_prediction: probably_damagingmetasvm: Dprimateai: D
Benign:
CADD: 5.60metalr: T
Neutral: Show all
VCEP Guidelines
Applied ACMG/AMP Criteria (VCEP Specific)
PVS1
PVS1 (Not Applied) Strength Modified
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: NM_001904.4:c.1004A>T results in a missense change (K335I), not a null variant. Therefore, this criterion is not applied.
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 pathogenic variant at codon 335. Therefore, this criterion is not applied.
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: no parental testing or inheritance data available. Therefore, this criterion is not applied.
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 characterization demonstrates that K335I increases CTNNB1 signaling activity and promotes tumor growth in cell lines and xenograft models. Therefore, this criterion is applied at Strong strength because well-established in vitro and in vivo studies show a damaging, oncogenic 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 prevalence data in affected individuals are available. Therefore, this criterion is not applied.
PM1
PM1 (Moderate)
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: K335 is located in the APC/Axin binding region of β-catenin, a critical functional domain, with no benign variation reported. Therefore, this criterion is applied at Moderate strength because the residue lies within a well-established functional domain.
PM2
PM2 (Moderate)
According to standard ACMG guidelines, the rule for PM2 is: "Absent from controls (or at extremely low frequency if recessive) in Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium". The evidence for this variant shows: not found in gnomAD or other population databases (MAF=0%). Therefore, this criterion is applied at Moderate strength because the variant is absent from large population cohorts.
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: CTNNB1-associated conditions are dominant and no trans data with another variant are relevant. 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: K335I is a missense change without alteration in protein length. 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: no other pathogenic missense variants have been reported at codon 335. 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 parental testing data provided. 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: CTNNB1 has known pathogenic missense but also some benign variants; gene-level metrics are not clearly supportive. 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". The evidence for this variant shows: in silico predictions are mixed and SpliceAI predicts no splicing impact. 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 clinical phenotype data were 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: ClinVar has no classification. 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". The evidence for this variant shows: allele frequency is 0%. 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: allele frequency is 0%. 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 data on occurrence 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 demonstrate damaging, oncogenic effects. 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 segregation 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: CTNNB1 disease mechanism often involves gain-of-function missense changes. 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 compound or cis variant data available. 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: this is not an in-frame indel in a repetitive region. 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". The evidence for this variant shows: in silico predictions are mixed but SpliceAI predicts no splicing impact. Therefore, this criterion is applied at Supporting strength because computational evidence does not support a damaging effect.
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 second 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 exist. 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: this is a missense variant. Therefore, this criterion is not applied.