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.1417_1419dup
Protein Change
L473dup
Location
Exon 9 (Exon 9 of )
9
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 L473dup 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
Unknown
PP3 Applied
No
REVEL Score
0.0
Threshold: ≥0.75 = PP3 applied

SpliceAI Scores

Window: ±500bp
Effect Type Score Position
- Acceptor Loss (AL) 0.02 -30 bp
- Donor Loss (DL) 0.0 33 bp
+ Acceptor Gain (AG) 0.0 -207 bp
+ Donor Gain (DG) 0.01 -99 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, 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: an in-frame duplication (L473dup) that does not introduce a premature stop codon or disrupt splicing at a canonical site. 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: no prior reports of a pathogenic L473dup or equivalent amino acid change at this residue. Therefore, this criterion is not applied.

PS2

PS2 (Not Applied)

According to VCEP guidelines, the rule for PS2 (Strong) is: de novo occurrence with confirmed maternity and paternity and detectable allele fraction absent in parents plus tissue comparison (Criteria 1 and 2) or (Moderate) if only Criteria 1 or 2 is met. The evidence for this variant shows: no data on parental testing or tissue allele fraction. Therefore, this criterion is not applied.

PS3

PS3 (Not Applied)

According to VCEP guidelines, the rule for PS3 is: functional assay meeting VCEP/BMVCEP quality metrics demonstrating a damaging effect. The evidence for this variant shows: no functional studies of L473dup have been performed. Therefore, this criterion is not applied.

PS4

PS4 (Not Applied)

According to VCEP guidelines, the rule for PS4 is: absent from controls (PM2) plus phenotype points ≥0.5 for Supporting up to ≥16 for Very Strong. The evidence for this variant shows: no case-level phenotype or literature reports. Therefore, this criterion is not applied.

PM1

PM1 (Not Applied)

According to VCEP guidelines, the rule for PM1 (Supporting) is: residue affecting a critical functional domain per gene‐specific Table 4. The evidence for this variant shows: L473 is not listed as a critical hotspot or 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: not found in gnomAD or other population databases (MAF=0%). 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 for a recessive disorder. The evidence for this variant shows: no data on trans configuration with another pathogenic allele. Therefore, this criterion is not applied.

PM4

PM4 (Not Applied)

According to standard ACMG guidelines, the rule for PM4 is: in-frame indels or stop-loss variants in non-repeat regions that change protein length. The evidence for this variant shows: an in-frame single amino acid duplication but without evidence of pathogenic impact or localization to a repetitive region. Therefore, this criterion is not applied.

PM5

PM5 (Not Applied)

According to VCEP guidelines, the rule for PM5 is: novel missense change at a residue with a known pathogenic missense. The evidence for this variant shows: this is an in-frame duplication rather than a missense substitution at L473. 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 or maternity. 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. 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 to missense variants. The evidence for this variant shows: it is an in-frame duplication, not a 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: SpliceAI predicts no splicing impact, but this criterion applies only to missense or splicing predictions for non-synonymous SNVs. Therefore, this criterion is not applied.

PP4

PP4 (Not Applied)

According to standard ACMG guidelines, the rule for PP4 is: patient’s phenotype highly specific for gene. The evidence for this variant shows: no 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 found in ClinVar or other 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 population. The evidence for this variant shows: MAF=0% in available databases. Therefore, this criterion is not applied.

BS1

BS1 (Not Applied)

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

BS2

BS2 (Not Applied)

According to VCEP guidelines, the rule for BS2 is: ≥3 homozygotes or heterozygotes in healthy individuals. 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 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 multiple affected family 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 in a gene where only truncating variants cause disease. The evidence for this variant shows: PIK3CA disease mechanism is predominantly activating missense. Therefore, this criterion is not applied.

BP2

BP2 (Not Applied)

According to VCEP guidelines, the rule for BP2 is: observed in cis/trans with a known 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. The evidence for this variant shows: L473dup is not in a repetitive region. Therefore, this criterion is not applied.

BP4

BP4 (Not Applied)

According to VCEP guidelines, the rule for BP4 is: two of three splicing tools predict no impact for synonymous or non-coding variants. The evidence for this variant shows: it is an in-frame coding duplication, not applicable under BP4. 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: no such reports. Therefore, this criterion is not applied.

BP7

BP7 (Not Applied)

According to VCEP guidelines, the rule for BP7 is: synonymous/intronic non-conserved with no splicing impact. The evidence for this variant shows: it is a coding duplication. Therefore, this criterion is not applied.