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.1171A>G
Protein Change
I391V
Location
Exon 7 (Exon 7 of )
7
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
Uncertain Significance (VUS)
1 publications
Clinical Statement

"This variant has been reported in ClinVar as Uncertain significance (1 clinical laboratories)."

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 PIK3CA I391V 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
0.312
Threshold: ≥0.75 = PP3 applied

SpliceAI Scores

Window: ±500bp
Effect Type Score Position
- Acceptor Loss (AL) 0.0 -29 bp
- Donor Loss (DL) 0.0 -56 bp
+ Acceptor Gain (AG) 0.0 -25 bp
+ Donor Gain (DG) 0.0 80 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, start codon, splicing +1/2, startgain, single or multi-exon deletion) in a gene where loss of function is a known mechanism of disease." The evidence for this variant shows: NM_006218.4:c.1171A>G is a missense variant (I391V), not a null variant. Therefore, this criterion is not applied.

PS1

PS1 (Not Applied)

According to VCEP 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: I391V has not been reported as a pathogenic change at this residue. Therefore, this criterion is not applied.

PS2

PS2 (Not Applied)

According to VCEP guidelines, the rule for PS2 is: "Award the PS2 point if the variant is de novo with confirmed maternity and paternity and meets tissue fraction criteria for somatic mutations." The evidence for this variant shows: no de novo or parental testing data are available. Therefore, this criterion is not applied.

PS3

PS3 (Not Applied)

According to VCEP guidelines, the rule for PS3 is: "Functional assays meeting the BMVCEP quality metrics and validation controls demonstrating a damaging effect on the gene or gene product." The evidence for this variant shows: no functional studies are available. Therefore, this criterion is not applied.

PS4

PS4 (Not Applied)

According to VCEP guidelines, the rule for PS4 is: "Case-control or case series data assigning points for phenotypic match in affected individuals absent from controls (PM2 required)." The evidence for this variant shows: no reported cases in the literature or series. 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: I391 is not located within a known PIK3CA critical hotspot domain. 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: it is absent from gnomAD and other population databases. 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 (Moderate)." The evidence for this variant shows: PIK3CA-associated disease is dominantly acting 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 (Moderate)." The evidence for this variant shows: it is a missense change with no length alteration. 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 (Moderate)." The evidence for this variant shows: no other pathogenic missense changes at residue I391 have been reported. 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 (Supporting)." 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 (Supporting)." The evidence for this variant shows: no segregation data are available. Therefore, this criterion is not applied.

PP2

PP2 (Supporting)

According to VCEP guidelines, the rule for PP2 is: "Missense constraint computed in ExAC/gnomAD >3.09 for PIK3CA (Supporting)." The evidence for this variant shows: PIK3CA has a missense constraint z-score >3.09 in gnomAD. Therefore, this criterion is applied at Supporting strength.

PP3

PP3 (Not Applied)

According to standard ACMG guidelines, the rule for PP3 is: "Multiple computational tools predict a deleterious effect (Supporting)." The evidence for this variant shows: in silico tools (CADD, PolyPhen, REVEL, SpliceAI) predict a benign impact. Therefore, this criterion is not applied.

PP4

PP4 (Not Applied)

According to standard ACMG guidelines, the rule for PP4 is: "Patient phenotype is highly specific for a disease with a single genetic etiology (Supporting)." The evidence for this variant shows: no specific clinical phenotype information is provided. Therefore, this criterion is not applied.

PP5

PP5 (Not Applied)

According to standard ACMG guidelines, the rule for PP5 is: "Reputable source reports the variant as pathogenic (Supporting)." The evidence for this variant shows: ClinVar lists it as VUS, not pathogenic. Therefore, this criterion is not applied.

BA1

BA1 (Not Applied)

According to VCEP guidelines, the rule for BA1 is: "Allele frequency >0.0926% in population databases (Stand Alone)." The evidence for this variant shows: it is absent from population databases. Therefore, this criterion is not applied.

BS1

BS1 (Not Applied)

According to VCEP guidelines, the rule for BS1 is: "Allele frequency >0.0185% in population databases (Strong)." The evidence for this variant shows: it is absent from population databases. 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 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 VCEP guidelines, the rule for BS3 is: "Well-validated functional assays demonstrating no damaging effect (Strong)." The evidence for this variant shows: no benign 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 family members (Strong)." 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 loss-of-function causes disease (Supporting)." The evidence for this variant shows: PIK3CA pathogenic 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 in a dominant disorder or in cis with a pathogenic variant (Supporting)." 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 without a known function (Supporting)." The evidence for this variant shows: it is a missense 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: "Applicable only to synonymous, intronic (non-canonical) or non-coding UTR variants when ≥2 splice tools predict no impact (Supporting)." The evidence for this variant shows: it is a missense change, not eligible. 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 with an alternative molecular basis for disease in the same individual (Supporting)." The evidence for this variant shows: no evidence of alternative etiology. Therefore, this criterion is not applied.

BP6

BP6 (Not Applied)

According to standard ACMG guidelines, the rule for BP6 is: "Reputable source reports the variant as benign (Supporting)." The evidence for this variant shows: no such reports. Therefore, this criterion is not applied.

BP7

BP7 (Not Applied)

According to VCEP guidelines, the rule for BP7 is: "Synonymous or intronic (non-canonical) variants with low conservation (PhyloP <0.1) (Supporting)." The evidence for this variant shows: it is a missense variant. Therefore, this criterion is not applied.