rs1262394031

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 5P and 2B. PM1PM2PP2BP4_Moderate

The NM_006218.4(PIK3CA):​c.995G>A​(p.Ser332Asn) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,612,504 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S332I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

PIK3CA
NM_006218.4 missense

Scores

2
1
16

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 6.25

Publications

4 publications found
Variant links:
Genes affected
PIK3CA (HGNC:8975): (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha) Phosphatidylinositol 3-kinase is composed of an 85 kDa regulatory subunit and a 110 kDa catalytic subunit. The protein encoded by this gene represents the catalytic subunit, which uses ATP to phosphorylate PtdIns, PtdIns4P and PtdIns(4,5)P2. This gene has been found to be oncogenic and has been implicated in cervical cancers. A pseudogene of this gene has been defined on chromosome 22. [provided by RefSeq, Apr 2016]
PIK3CA Gene-Disease associations (from GenCC):
  • overgrowth syndrome and/or cerebral malformations due to abnormalities in MTOR pathway genes
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • megalencephaly-capillary malformation-polymicrogyria syndrome
    Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • vascular malformation
    Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
  • Cowden disease
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Cowden syndrome 5
    Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
  • familial ovarian cancer
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
  • hereditary breast carcinoma
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM1
In a domain C2 PI3K-type (size 157) in uniprot entity PK3CA_HUMAN there are 21 pathogenic changes around while only 2 benign (91%) in NM_006218.4
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the PIK3CA gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 98 curated pathogenic missense variants (we use a threshold of 10). The gene has 13 curated benign missense variants. Gene score misZ: 5.5986 (above the threshold of 3.09). Trascript score misZ: 6.1406 (above the threshold of 3.09). GenCC associations: The gene is linked to megalencephaly-capillary malformation-polymicrogyria syndrome, vascular malformation, Cowden syndrome 5, overgrowth syndrome and/or cerebral malformations due to abnormalities in MTOR pathway genes, Cowden disease, hereditary breast carcinoma, familial ovarian cancer.
BP4
Computational evidence support a benign effect (MetaRNN=0.18946907).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PIK3CANM_006218.4 linkc.995G>A p.Ser332Asn missense_variant Exon 5 of 21 ENST00000263967.4 NP_006209.2
PIK3CAXM_006713658.5 linkc.995G>A p.Ser332Asn missense_variant Exon 5 of 21 XP_006713721.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PIK3CAENST00000263967.4 linkc.995G>A p.Ser332Asn missense_variant Exon 5 of 21 2 NM_006218.4 ENSP00000263967.3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152162
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000401
AC:
1
AN:
249068
AF XY:
0.00000740
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000884
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1460342
Hom.:
0
Cov.:
30
AF XY:
0.00000138
AC XY:
1
AN XY:
726608
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33458
American (AMR)
AF:
0.00
AC:
0
AN:
44712
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26120
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39656
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86216
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52966
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
9.00e-7
AC:
1
AN:
1111102
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60350
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152162
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74314
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41432
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
May 28, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.995G>A (p.S332N) alteration is located in exon 5 (coding exon 4) of the PIK3CA gene. This alteration results from a G to A substitution at nucleotide position 995, causing the serine (S) at amino acid position 332 to be replaced by an asparagine (N). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Cowden syndrome Uncertain:1
Jan 17, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been reported in the literature in individuals affected with PIK3CA-related conditions. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 947186). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 332 of the PIK3CA protein (p.Ser332Asn). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Benign
-0.10
T
BayesDel_noAF
Benign
-0.38
CADD
Benign
22
DANN
Benign
0.78
DEOGEN2
Benign
0.31
T;.
Eigen
Benign
-0.14
Eigen_PC
Benign
0.11
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.91
D;D
M_CAP
Benign
0.021
T
MetaRNN
Benign
0.19
T;T
MetaSVM
Benign
-0.93
T
MutationAssessor
Benign
0.14
N;.
PhyloP100
6.3
PrimateAI
Pathogenic
0.80
T
PROVEAN
Benign
-0.60
N;.
REVEL
Benign
0.097
Sift
Benign
0.61
T;.
Sift4G
Benign
0.48
T;.
Polyphen
0.0
B;.
Vest4
0.19
MutPred
0.34
Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);
MVP
0.44
MPC
0.72
ClinPred
0.46
T
GERP RS
5.5
Varity_R
0.42
gMVP
0.37
Mutation Taster
=65/35
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs1262394031; hg19: chr3-178921513; API