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.2782C>T
Protein Change
Q928*
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
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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 PIK3CA Q928* 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) 0.01 -115 bp
- Donor Loss (DL) 0.1 8 bp
+ Acceptor Gain (AG) 0.01 196 bp
+ Donor Gain (DG) 0.02 -2 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 exon or multiexon deletion) in a gene where loss‐of‐function is a known mechanism of disease." The evidence for this variant shows: c.2782C>T creates a premature stop codon (Q928*). However, PIK3CA disease mechanism is gain‐of‐function, not loss‐of‐function. Therefore, this criterion is not applied.

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 previously established pathogenic variant results in Q928*. Therefore, this criterion is not applied.

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 de novo confirmation data. Therefore, this criterion is not applied.

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.

PS4

PS4 (Not Applied)

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

PM1

PM1 (Not Applied)

According to VCEP guidelines, the rule for PM1 is: "Residues affecting critical functional domains provided in Table 4 for each gene (Supporting)." The evidence for this variant shows: domain information is unavailable. 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 (Supporting)." The evidence for this variant shows: absent from gnomAD and other population databases (MAF=0%). Therefore, this criterion is applied at Supporting strength.

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 information on trans configuration or recessive inheritance. 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: nonsense variant leading to truncation, which is evaluated under PVS1 rather than PM4. Therefore, this criterion is not applied.

PM5

PM5 (Not Applied)

According to standard ACMG guidelines, the rule for PM5 is: "Novel missense change at amino acid residue where a different pathogenic missense change has been seen." 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, 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)

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. 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) applied for PIK3CA and related genes (Supporting)." The evidence for this variant shows: it 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: in silico tools gave mixed or neutral predictions for splicing; nonsense effect is recognized but computational splicing evidence is not strong. 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 recently reports variant as pathogenic without available evidence." The evidence for this variant shows: no entries in ClinVar or other reputable sources. Therefore, this criterion is not applied.

BA1

BA1 (Not Applied)

According to VCEP guidelines, the rule for BA1 is: "Allele frequency >0.0926% (Stand Alone) indicates benign." The evidence for this variant shows: allele frequency is 0%. Therefore, this criterion is not applied.

BS1

BS1 (Not Applied)

According to VCEP guidelines, the rule for BS1 is: "Allele frequency >0.0185% (Strong) indicates benign." The evidence for this variant shows: allele frequency is 0%. Therefore, this criterion is not applied.

BS2

BS2 (Not Applied)

According to VCEP guidelines, the rule for BS2 is: "Observed in ≥3 homozygotes in gnomAD or ≥3 heterozygotes in well‐phenotyped family members (Strong)." The evidence for this variant shows: no such 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." 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 of a family." The evidence for this variant shows: no segregation information. 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 only truncating variants are known to cause disease." The evidence for this variant shows: it is truncating, not missense. Therefore, this criterion is not applied.

BP2

BP2 (Not Applied)

According to standard ACMG guidelines, the rule for BP2 is: "Observed in cis or trans with a pathogenic variant in the same gene." 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 deletions/insertions in repetitive regions." The evidence for this variant shows: it 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: "Two of three splicing prediction tools predict no impact on splicing for synonymous, intronic, or UTR variants (Supporting)." The evidence for this variant shows: it is a nonsense variant and SpliceAI score is low, but BP4 does not apply to nonsense changes. 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 alternative 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 without primary evidence." The evidence for this variant shows: none. Therefore, this criterion is not applied.

BP7

BP7 (Not Applied)

According to standard ACMG guidelines, the rule for BP7 is: "Synonymous variant with no predicted splicing impact and non‐conserved nucleotide." The evidence for this variant shows: nonsense change, not synonymous. Therefore, this criterion is not applied.