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 or multi-exon deletion) in a gene where loss of function is a known mechanism of disease." The evidence for this variant shows: "c.2782C>T (p.Q928*) is a nonsense variant in PIK3CA." Therefore, this criterion is not applied because loss of function is not an established mechanism of disease for PIK3CA.

PS1

PS1 (Not Applied)

According to VCEP guidelines, the rule for PS1 (Strong) is: "Same amino acid change as a known pathogenic variant via a different nucleotide change." The evidence for this variant shows: "This variant generates a stop codon and does not match a known pathogenic amino acid change." Therefore, this criterion is not applied because the variant does not meet PS1.

PS2

PS2 (Not Applied)

According to VCEP guidelines, the rule for PS2_Strong is: "The variant is present at a detectable allele fraction but is absent from parental samples with confirmed maternity and paternity, and is present at a detectable allele fraction in an affected tissue sample but is absent from or at a lower allelic fraction in another tissue." The evidence for this variant shows: "No de novo or mosaic parental data are available." Therefore, this criterion is not applied because de novo criteria are not met.

PS3

PS3 (Not Applied)

According to VCEP guidelines, the rule for PS3 (Strong) is: "Well-established functional studies showing a deleterious effect." The evidence for this variant shows: "No functional characterization is available for p.Q928*." Therefore, this criterion is not applied due to lack of functional evidence.

PS4

PS4 (Not Applied)

According to VCEP guidelines, the rule for PS4 is: "Statistical evidence from case-control studies or phenotype-driven point system requiring PM2." The evidence for this variant shows: "No reported cases or statistical data available." Therefore, this criterion is not applied due to absence of case-level evidence.

PM1

PM1 (Not Applied)

According to VCEP guidelines, the rule for PM1 (Supporting) is: "Residues affecting critical functional domains provided in Table 4 for each gene." The evidence for this variant shows: "p.Q928* is not located in a specified critical functional domain or hotspot." Therefore, this criterion is not applied.

PM2

PM2 (Supporting)

According to VCEP guidelines, the rule for PM2 (Supporting) is: "Absent/rare from controls in an ethnically-matched cohort population sample (≥1)." The evidence for this variant shows: "The variant is not present in gnomAD or other population databases (MAF=0)." Therefore, this criterion is applied at Supporting strength because the variant is absent from population 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." The evidence for this variant shows: "PIK3CA is not associated with a recessive phenotype and no trans data are 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 or stop-loss variants affecting non-repeat regions." The evidence for this variant shows: "This is a stop-gain variant, which is evaluated under PVS1 if LOF is mechanism, but LOF is not established for PIK3CA." Therefore, this criterion is not applied.

PM5

PM5 (Not Applied)

According to VCEP guidelines, the rule for PM5 (Moderate) 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 change, not a missense variant." 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." The evidence for this variant shows: "No de novo data are available." Therefore, this criterion is not applied.

PP1

PP1 (Not Applied)

According to standard ACMG guidelines, the rule for PP1 is: "Cosegregation with disease in multiple affected family members." The evidence for this variant shows: "No segregation data are available." Therefore, this criterion is not applied.

PP2

PP2 (Not Applied)

According to VCEP guidelines, the rule for PP2 (Supporting) is: "Missense constraint with ExAC/gnomAD z-score >3.09 for specific genes." The evidence for this variant shows: "This is a nonsense variant, not a missense." Therefore, this criterion is not applied.

PP3

PP3 (Not Applied)

According to VCEP guidelines and standard ACMG, PP3 applies to variants with deleterious computational predictions. The evidence for this variant shows: "Mixed computational predictions and low CADD score, but variant is nonsense." Therefore, PP3 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 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 but no evidence available." The evidence for this variant shows: "Not listed in ClinVar or comparable databases." Therefore, this criterion is not applied.

BA1

BA1 (Not Applied)

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

BS1

BS1 (Not Applied)

According to VCEP guidelines, the rule for BS1 (Strong) is: "Allele frequency >0.0185%." The evidence for this variant shows: "MAF=0% in population databases." Therefore, this criterion is not applied.

BS2

BS2 (Not Applied)

According to VCEP guidelines, the rule for BS2 (Strong) is: "Observation of variant in ≥3 unaffected individuals or well-phenotyped family members." The evidence for this variant shows: "No such data are available." Therefore, this criterion is not applied.

BS3

BS3 (Not Applied)

According to VCEP guidelines, the rule for BS3 (Strong/Supporting) is: "Well-established functional studies showing no damaging effect." The evidence for this variant shows: "No functional studies 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." 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 gene where only loss of function causes disease." The evidence for this variant shows: "This is a nonsense variant and PIK3CA disease mechanism is gain-of-function." 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 gene." The evidence for this variant shows: "No trans data available." 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 without predicted functional impact." The evidence for this variant shows: "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 (Supporting) is: "Two out of three splicing prediction tools predict no splicing impact for synonymous, intronic or UTR variants." The evidence for this variant shows: "This is a coding 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 data available." 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 evidence." The evidence for this variant shows: "Not reported in such sources." Therefore, this criterion is not applied.

BP7

BP7 (Not Applied)

According to VCEP guidelines, the rule for BP7 (Supporting) is: "Synonymous variant at non-conserved nucleotide (PhyloP <0.1) in UTR/intronic positions." The evidence for this variant shows: "This is a nonsense variant." Therefore, this criterion is not applied.