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.2953T>A
Protein Change
Y985N
Location
Exon 21 (Exon 21 of )
21
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

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 Y985N 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
Benign
PP3 Applied
No
REVEL Score
0.448
Threshold: ≥0.75 = PP3 applied

SpliceAI Scores

Window: ±500bp
Effect Type Score Position
- Acceptor Loss (AL) 0.0 -9 bp
- Donor Loss (DL) 0.0 -68 bp
+ Acceptor Gain (AG) 0.01 -16 bp
+ Donor Gain (DG) 0.0 -3 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: NM_006218.4:c.2953T>A results in a missense change (Y985N) and variant consequence/type is unknown. Therefore, this criterion is not applied because the variant is not a null variant or loss-of-function type.

PS1

PS1 (Not Applied)

According to VCEP guidelines, the rule for PS1 is: "Strong: Same amino acid change as a previously established pathogenic variant regardless of nucleotide change." The evidence for this variant shows: there is no previously established pathogenic variant resulting in Y985N. Therefore, this criterion is not applied because the variant does not match a known pathogenic amino acid change.

PS2

PS2 (Not Applied)

According to VCEP guidelines, the rule for PS2 is: "Strong: Award the PS2_Strong point if Criteria 1 AND Criteria 2 are fulfilled (confirmed de novo in patient with disease and confirmed in tissue heterogeneity context)." The evidence for this variant shows: no data on de novo occurrence or somatic tissue fraction. Therefore, this criterion is not applied due to lack of de novo or tissue evidence.

PS3

PS3 (Not Applied)

According to VCEP guidelines, the rule for PS3 is: "Strong: Functional assay meets the acceptability criteria delimited in (PMID: 31892348) with VCEP specifications." The evidence for this variant shows: no functional characterization studies have been performed. Therefore, this criterion is not applied because functional data are absent.

PS4

PS4 (Not Applied)

According to VCEP guidelines, the rule for PS4 is: "Very Strong: ≥16 phenotype points for cases absent from controls; Strong: 3.5–15.75 points; Moderate: 1.5–3.25 points; Supporting: 0.5–1.25 points." The evidence for this variant shows: no case reports or phenotype data. Therefore, this criterion is not applied due to absence of case-level phenotype evidence.

PM1

PM1 (Not Applied)

According to VCEP guidelines, the rule for PM1 is: "Supporting: Residues affecting critical functional domains provided in Table 4 for each gene." The evidence for this variant shows: the position Y985 has not been annotated as within a defined critical functional domain. Therefore, this criterion is not applied because domain mapping information is unavailable.

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 for this variant shows: NM_006218.4:c.2953T>A 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: no data on cis/trans configuration with other PIK3CA variants. Therefore, this criterion is not applied due to absence of trans evidence.

PM4

PM4 (Not Applied)

According to standard ACMG guidelines, the rule for PM4 is: "Protein length changes due to in-frame indels or stop-loss variants." The evidence for this variant shows: NM_006218.4:c.2953T>A is a missense substitution without protein length alteration. Therefore, this criterion is not applied.

PM5

PM5 (Not Applied)

According to VCEP guidelines, the rule for PM5 is: "Moderate: Novel missense change at an amino acid residue where a different missense change has been established as pathogenic." The evidence for this variant shows: no other pathogenic missense variant at residue Y985 has been reported. Therefore, this criterion is not applied.

PM6

PM6 (Not Applied)

According to standard ACMG guidelines, the rule for PM6 is: "Presumed de novo, 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: "Co-segregation 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 is: "Supporting: Missense constraint computed in ExAC/gnomAD with z-score >3.09." The evidence for this variant shows: no ExAC/gnomAD z-score has been provided. Therefore, this criterion is not applied due to missing missense constraint data.

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: the majority of in silico tools predict benign impact (SIFT, PolyPhen, MetaSVM benign; REVEL 0.45; low CADD; SpliceAI 0.01). Therefore, this criterion is not applied because computational evidence does not support deleterious effect.

PP4

PP4 (Not Applied)

According to standard ACMG guidelines, the rule for PP4 is: "Patient phenotype or family history is highly specific for gene." The evidence for this variant shows: no phenotype or clinical presentation data are 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." The evidence for this variant shows: not present in ClinVar or other reputable databases. Therefore, this criterion is not applied.

BA1

BA1 (Not Applied)

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

BS1

BS1 (Not Applied)

According to VCEP guidelines, the rule for BS1 is: "Strong: Allele frequency >0.0185%." The evidence for this variant shows: allele frequency is 0% in population databases. Therefore, this criterion 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 individuals." The evidence for this variant shows: no homozygotes or heterozygotes reported. Therefore, this criterion is not applied.

BS3

BS3 (Not Applied)

According to VCEP guidelines, the rule for BS3 is: "Strong: Well-validated functional studies show no damaging effect; Supporting: less robust functional evidence." The evidence for this variant shows: no functional studies are 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 a gene for which primarily loss-of-function causes disease." The evidence for this variant shows: PIK3CA disease mechanism is often gain-of-function, and this is a missense variant. Therefore, this criterion is not applied.

BP2

BP2 (Not Applied)

According to VCEP guidelines, the rule for BP2 is: "Supporting: Observed in cis or trans with a known pathogenic variant in the same gene." The evidence for this variant shows: no information on cis/trans status with other variants. Therefore, this criterion is not applied.

BP3

BP3 (Not Applied)

According to standard ACMG guidelines, the rule for BP3 is: "In-frame insertions/deletions in repetitive regions without known function." The evidence for this variant shows: this is a single nucleotide substitution. Therefore, this criterion is not applied.

BP4

BP4 (Not Applied)

According to VCEP guidelines, the rule for BP4 is: "Supporting: Applicable only to synonymous, intronic (except canonical splice sites), or UTR variants when two of three splice tools predict no impact." The evidence for this variant shows: Y985N is a missense change. Therefore, this criterion is not applied under VCEP specifications.

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 information on alternative molecular findings. 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: not present in ClinVar or similar sources. Therefore, this criterion is not applied.

BP7

BP7 (Not Applied)

According to VCEP guidelines, the rule for BP7 is: "Supporting: For synonymous or intronic positions (non-canonical) with PhyloP <0.1." The evidence for this variant shows: Y985N is a missense substitution. Therefore, this criterion is not applied.