Genetic Information

Gene & Transcript Details

Gene
PIK3CA
Transcript
NM_006218.4 MANE Select
Total Exons
Reference Sequence
NC_000003.11
Alternative Transcripts
IDStatusDetails
NM_006218.2 Alternative 3724 nt | 158–3364
NM_006218.3 Alternative 9104 nt | 158–3364
NM_006218.4 MANE Select 9259 nt | 324–3530

Variant Details

HGVS Notation
NM_006218.4:c.3067C>T
Protein Change
R1023*
Location
Exon 21 (Exon 21 of )
21
5'Exon Structure3'
Functional Consequence
Loss of Function
Alternate Identifiers

Clinical & Population Data

Population Frequency

gnomAD
Global Frequency
0.0 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
Unknown
0 publications
Clinical Statement

""

COSMIC Somatic Evidence

Open
COSMIC ID
COSM1420971
Recurrence
6 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 PIK3CA.

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) 0.21 -130 bp
- Donor Loss (DL) 0.0 -272 bp
+ Acceptor Gain (AG) 0.0 -234 bp
+ Donor Gain (DG) 0.0 398 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 (nonsense, frameshift, canonical ±1 or 2 splice sites, initiation codon, single or multi-exon deletion) in a gene where loss-of-function is a known mechanism of disease"; the evidence for this variant shows that PIK3CA is a proto-oncogene in which gain-of-function, not loss-of-function, is the established disease mechanism; therefore, this criterion is not applied because loss-of-function is not a known mechanism for PIK3CA-related disease.

PS1

PS1 (Not Applied)

According to VCEP guidelines, the rule for PS1 is: "Strong Strength: Strong No change. Modification Type: None"; the evidence for this variant shows a nonsense change rather than a missense change identical to a known pathogenic variant; therefore, this criterion is not applied.

PS2

PS2 (Not Applied)

According to VCEP guidelines, the rule for PS2 is: "Strong Strength: Strong Award the PS2_Strong point if Criteria 1 AND Criteria 2 are fulfilled..."; no de novo or mosaic segregation data are available for this somatic variant; therefore, this criterion is not applied.

PS3

PS3 (Not Applied)

According to VCEP guidelines, the rule for PS3 is: "Strong Strength: Strong Follow recommendations set forth by the SVI... Award PS3 if the functional assay meets the acceptability criteria..."; no functional assay data are available for this variant; therefore, this criterion is not applied.

PS4

PS4 (Not Applied)

According to VCEP guidelines, the rule for PS4 is: "Very Strong Strength: Very Strong Points are assigned for phenotype according to (Table 2A)... PS4_VeryStrong ≥ 16 points"; there are no reported case counts or phenotypic data for this variant; therefore, this criterion is not applied.

PM1

PM1 (Not Applied)

According to VCEP guidelines, the rule for PM1 is: "Supporting Strength: Supporting Residues affecting critical functional domains provided in Table 4 for each gene"; this nonsense variant does not map to a defined critical domain residue in PIK3CA; therefore, this criterion is not applied.

PM2

PM2 (Supporting)

According to VCEP guidelines, the rule for PM2 is: "Supporting Strength: Supporting Absent/rare from controls in an ethnically-matched cohort population sample (≥1)"; the evidence for this variant shows it is absent from gnomAD and other population databases; therefore, this criterion is applied at Supporting strength because the variant is absent from controls.

PM3

PM3 (Not Applied)

According to standard ACMG guidelines, the rule for PM3 is: "For recessive disorders detected in trans with a pathogenic variant"; PIK3CA-related disease is not recessive and no trans data exist; 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"; this variant is a nonsense change and does not produce an in-frame indel or stop-loss; 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 missense change is pathogenic"; this variant is nonsense, not missense, and no other truncating variant at this residue is reported; 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"; there are no de novo data for this somatic variant; 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"; no segregation data are available; therefore, this criterion is not applied.

PP2

PP2 (Not Applied)

According to VCEP guidelines, the rule for PP2 is: "Supporting Strength: Supporting Missense constraint computed in ExAC/gnomAD (z-score > 3.09)"; this variant is nonsense, 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 or gene product"; in silico predictions are mixed and do not strongly support pathogenicity; therefore, this criterion is not applied.

PP4

PP4 (Not Applied)

According to standard ACMG guidelines, the rule for PP4 is: "Patient’s phenotype or family history is highly specific for a disease with a single genetic etiology"; no phenotype data are provided; therefore, this criterion is not applied.

PP5

PP5 (Not Applied)

According to standard ACMG guidelines, the rule for PP5 is: "Reputable source recently reports variant as pathogenic"; this variant is not found in ClinVar or other databases; therefore, this criterion is not applied.

BA1

BA1 (Not Applied)

According to VCEP guidelines, the rule for BA1 is: "Stand Alone Strength: Stand Alone Allele frequency (>0.0926%)"; this variant is absent from population databases; therefore, this criterion is not applied.

BS1

BS1 (Not Applied)

According to VCEP guidelines, the rule for BS1 is: "Strong Strength: Strong Allele frequency (>0.0185%)"; the variant is absent from controls; therefore, this criterion is not applied.

BS2

BS2 (Not Applied)

According to VCEP guidelines, the rule for BS2 is: "Strong Strength: Strong Award BS2 if ≥3 homozygotes present in gnomAD or ≥3 heterozygous in well phenotyped family members"; no such observations exist; therefore, this criterion is not applied.

BS3

BS3 (Not Applied)

According to VCEP guidelines, the rule for BS3 is: "Strong Strength: Strong Follow recommendations set forth by the SVI..."; no functional studies demonstrating no impact are available; 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 members of a family"; no segregation data are available; 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 for which primarily truncating variants cause disease"; this variant is truncating but PIK3CA disease mechanism is gain-of-function missense; therefore, this criterion is not applied.

BP2

BP2 (Not Applied)

According to standard ACMG guidelines, the rule for BP2 is: "Observed in trans or cis with a pathogenic variant"; no such observations exist; 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 a known function"; this is a nonsense variant, not an in-frame indel; therefore, this criterion is not applied.

BP4

BP4 (Not Applied)

According to VCEP guidelines, the rule for BP4 is: "Supporting Strength: Supporting Award BP4 for synonymous, intronic positions... if two of three splicing prediction tools predict no impact"; this is a nonsense variant, not applicable; therefore, this criterion is not applied.

BP5

BP5 (Not Applied)

According to standard ACMG guidelines, the rule for BP5 is: "Variant found in a gene for which an alternative molecular basis is known to cause disease"; not applicable here; therefore, this criterion is not applied.

BP6

BP6 (Not Applied)

According to standard ACMG guidelines, the rule for BP6 is: "Reputable source reports variant as benign"; no such reports exist; therefore, this criterion is not applied.

BP7

BP7 (Not Applied)

According to VCEP guidelines, the rule for BP7 is: "Supporting Strength: Supporting For synonymous, intronic positions... if the nucleotide is non-conserved"; this is a nonsense variant; therefore, this criterion is not applied.