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.2779G>T
Protein Change
G927*
Location
Exon 19 (Exon 19 of )
19
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
Recurrence
0 occurrences
PM1 Criteria
Not Applied
COSMIC Database Preview
COSMIC Preview
Accessing full COSMIC database details requires institutional login or subscription.

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 PIK3CA G927* 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) 0.02 109 bp
- Donor Loss (DL) 0.08 11 bp
+ Acceptor Gain (AG) 0.01 199 bp
+ Donor Gain (DG) 0.05 -13 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 VCEP guidelines, the rule for PVS1 is: "Null variant (nonsense, fs, start codon, splicing +1/2, startgain, single or multi-exon deletion) in a gene where LOF is a known mechanism of disease". The evidence for this variant shows: p.G927* is a null variant but PIK3CA disease mechanism is gain-of-function rather than loss-of-function. Therefore, this criterion is not applied because LOF is not an established mechanism for PIK3CA-related disease.

PS1

PS1 (Not Applied)

According to standard ACMG guidelines, the rule for PS1 is: "Same amino acid change as a previously established pathogenic variant regardless of nucleotide change". The evidence for this variant shows: no known pathogenic variant results in p.G927*. Therefore, this criterion is not applied because there is no prior pathogenic variant at this codon.

PS2

PS2 (Not Applied)

According to VCEP guidelines, the rule for PS2_Strong is: "De novo occurrence with confirmed maternity and paternity and allelic fraction criteria in tissue samples". The evidence for this variant shows: no de novo or parental data available. Therefore, this criterion is not applied due to lack of de novo confirmation.

PS3

PS3 (Not Applied)

According to VCEP guidelines, the rule for PS3 is: "Well-validated functional studies showing 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 due to absence of functional data.

PS4

PS4 (Not Applied)

According to VCEP guidelines, the rule for PS4 is: "Case reports with phenotypic specificity and points-based system for variants absent from controls". The evidence for this variant shows: no reported cases in the literature. Therefore, this criterion is not applied due to lack of case data.

PM1

PM1 (Not Applied)

According to VCEP guidelines, the rule for PM1_Supporting is: "Residues affecting critical functional domains provided in gene-specific table". The evidence for this variant shows: codon 927 is not listed as a critical functional domain in PIK3CA. Therefore, this criterion is not applied.

PM2

PM2 (Supporting)

According to VCEP guidelines, the rule for PM2 is: "Absent/rare from controls in an ethnically-matched cohort population sample (≥1)". The evidence for this variant shows: 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: "Detected in trans with a pathogenic variant in recessive disorders". The evidence for this variant shows: PIK3CA-related disorders are not recessive and no trans data is available. 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 not at repeat regions". The evidence for this variant shows: this is a nonsense variant causing truncation, not an in-frame indel. 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". The evidence for this variant shows: this is a nonsense variant, not missense. 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 maternity/paternity". The evidence for this variant shows: no parental or de novo data. 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 segregation data available. Therefore, this criterion is not applied.

PP2

PP2 (Not Applied)

According to VCEP guidelines, the rule for PP2 is: "Missense constraint z-score >3.09 in gnomAD for MTOR and PIK3CA". The evidence for this variant shows: this is a nonsense variant, 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". The evidence for this variant shows: computational tools yield mixed or benign predictions and the VCEP does not apply PP3 to truncating variants. 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". 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". The evidence for this variant shows: not present in ClinVar or other reputable databases. Therefore, this criterion is not applied.

BA1

BA1 (Not Applied)

According to VCEP guidelines, the rule for BA1 is: "Allele frequency >0.0926% in controls". The evidence for this variant shows: absent from controls. Therefore, this criterion is not applied.

BS1

BS1 (Not Applied)

According to VCEP guidelines, the rule for BS1 is: "Allele frequency >0.0185% in controls". The evidence for this variant shows: absent from controls. Therefore, this criterion is not applied.

BS2

BS2 (Not Applied)

According to VCEP guidelines, the rule for BS2 is: "Observed in ≥3 unrelated homozygotes or well-phenotyped heterozygotes". The evidence for this variant shows: no such observations. Therefore, this criterion is not applied.

BS3

BS3 (Not Applied)

According to VCEP guidelines, the rule for BS3 is: "Well-validated functional studies show no damaging effect". The evidence for this variant shows: no functional data. 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". 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 LOF causes disease". The evidence for this variant shows: this is a nonsense variant, not missense. 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 a dominant disorder 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)

According to standard ACMG guidelines, the rule for BP3 is: "In-frame indels in repetitive regions without functional impact". The evidence for this variant shows: this is a nonsense variant. Therefore, this criterion is not applied.

BP4

BP4 (Not Applied)

According to VCEP guidelines, the rule for BP4 is: "Synonymous or noncoding variants with no predicted splicing impact". The evidence for this variant shows: this is a nonsense variant. Therefore, this criterion is not applied.

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 such context. 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". The evidence for this variant shows: not present in such sources. Therefore, this criterion is not applied.

BP7

BP7 (Not Applied)

According to VCEP guidelines, the rule for BP7 is: "Synonymous or intronic variants at non-conserved sites". The evidence for this variant shows: this is a nonsense variant. Therefore, this criterion is not applied.