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.1255_1264delinsA
Protein Change
H419_L422delinsM
Location
Exon 8 (Exon 8 of )
8
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 H419_L422delinsM variant has been functionally characterized and identified as a statistically significant hotspot likely to be oncogenic, suggesting a damaging effect.

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
Unknown
PP3 Applied
No
REVEL Score
0.0
Threshold: ≥0.75 = PP3 applied

SpliceAI Scores

Window: ±500bp
Effect Type Score Position
- Acceptor Loss (AL) 0.0 223 bp
- Donor Loss (DL) 0.0 154 bp
+ Acceptor Gain (AG) 0.01 46 bp
+ Donor Gain (DG) 0.0 330 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 (e.g., nonsense, frameshift, canonical ±1 or 2 splice sites, initiation codon, single or multiexon deletion) in a gene where loss of function is a known mechanism of disease." The evidence for this variant shows it is an in-frame delins (H419_L422delinsM), not a null variant; therefore, PVS1 is not applied.

PS1

PS1 (Not Applied)

According to VCEP guidelines, the rule for PS1 is: "Strong Strength: Strong No change. Modification Type: None." The evidence shows there is no previously reported variant with an identical amino acid change; therefore, PS1 is not applied.

PS2

PS2 (Not Applied)

According to VCEP guidelines, the rule for PS2 is: "Award the PS2_Strong point if Criteria 1 AND Criteria 2 are fulfilled..." The evidence shows no parental or de novo data are available; therefore, PS2 is not applied.

PS3

PS3 (Strong)

According to VCEP guidelines, the rule for PS3 is: "Award PS3 if the functional assay meets the acceptability criteria delimited in (PMID: 31892348) with specifications added by the BMVCEP." The evidence shows well-established in vitro functional studies identify the H419_L422delinsM variant as a statistically significant hotspot likely to be oncogenic; therefore, PS3 is applied at Strong strength.

PS4

PS4 (Not Applied)

According to VCEP guidelines, the rule for PS4 is: "Points are assigned for phenotype according to (Table 2A)...Strength of evidence is determined by points according to (Table 2B)." The evidence for this variant shows no case or phenotype data with scored points; therefore, PS4 is not applied.

PM1

PM1 (Not Applied)

According to VCEP guidelines, the rule for PM1 is: "Supporting Strength: Residues affecting critical functional domains provided in Table 4 for each gene." The evidence shows H419_L422 is not listed as a VCEP-defined critical functional domain; therefore, PM1 is not applied.

PM2

PM2 (Supporting)

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

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 shows no recessive or trans configuration data; therefore, PM3 is not applied.

PM4

PM4 (Moderate)

According to standard ACMG guidelines, the rule for PM4 is: "Protein length changes due to inframe deletions/insertions in a non-repeat region." The evidence shows an in-frame delins replacing four amino acids with one (H419_L422delinsM) outside of a repetitive region; therefore, PM4 is applied at Moderate strength.

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 determined to be pathogenic has been seen before." The evidence shows this is an in-frame delins, not a novel missense substitution; therefore, PM5 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 shows no parental or de novo information; therefore, PM6 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 shows no family segregation data; therefore, PP1 is not applied.

PP2

PP2 (Not Applied)

According to VCEP guidelines, the rule for PP2 is: "Supporting - Missense constraint computed in ExAC/gnomAD; award if z-score > 3.09." The evidence shows this is an in-frame delins rather than a missense variant; therefore, PP2 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." The evidence shows in silico tools and SpliceAI predict no impact on splicing or function; 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 a single genetic etiology." No phenotype specificity data are available; therefore, PP4 is not applied.

PP5

PP5 (Not Applied)

According to standard ACMG guidelines, the rule for PP5 is: "Reputable source recently reports variant as pathogenic." No such report exists in ClinVar or other databases; therefore, PP5 is not applied.

BA1

BA1 (Not Applied)

According to VCEP guidelines, the rule for BA1 is: "Stand Alone: Allele frequency >0.0926%." The evidence shows the variant frequency is 0%; therefore, BA1 is not applied.

BS1

BS1 (Not Applied)

According to VCEP guidelines, the rule for BS1 is: "Strong: Allele frequency >0.0185%." The evidence shows the variant frequency is 0%; therefore, BS1 is not applied.

BS2

BS2 (Not Applied)

According to VCEP guidelines, the rule for BS2 is: "Strong: ≥3 homozygotes in gnomAD or ≥3 heterozygotes in well-phenotyped members." The evidence shows no such occurrences; therefore, BS2 is not applied.

BS3

BS3 (Not Applied)

According to VCEP guidelines, the rule for BS3 is: "Strong: Well-established in vitro or in vivo functional studies show no damaging effect." The evidence shows functional studies demonstrate a damaging, oncogenic effect; therefore, BS3 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, BS4 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." PIK3CA disease mechanism is gain-of-function; therefore, BP1 is not applied.

BP2

BP2 (Not Applied)

According to standard ACMG guidelines, the rule for BP2 is: "Observed in trans with a pathogenic variant." No such data exist; therefore, BP2 is not applied.

BP3

BP3 (Not Applied)

According to VCEP guidelines, the rule for BP3 is: "Supporting: In-frame indels in a repetitive region without known function." The region spanning H419-L422 is not repetitive; therefore, BP3 is not applied.

BP4

BP4 (Not Applied)

According to VCEP guidelines, the rule for BP4 is: "Supporting: Synonymous, intronic (non-canonical), or UTR variants predicted by two of three splicing tools to have no impact." This variant is a coding in-frame delins, not eligible; therefore, BP4 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." No such reports exist; therefore, BP5 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 source exists; therefore, BP6 is not applied.

BP7

BP7 (Not Applied)

According to VCEP guidelines, the rule for BP7 is: "Supporting: Synonymous, intronic (non-canonical), or UTR variants with low conservation." This variant is not synonymous or intronic; therefore, BP7 is not applied.