3-179204573-C-G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 3P and 5B. PM1PP2BS1_SupportingBS2

The NM_006218.4(PIK3CA):​c.1130C>G​(p.Pro377Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000123 in 1,536,950 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. P377L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000099 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00013 ( 0 hom. )

Consequence

PIK3CA
NM_006218.4 missense

Scores

4
9
6

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 7.49

Publications

14 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: Likely_benign. The variant received -2 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_006218.4
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.
BS1
Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.0000985 (15/152220) while in subpopulation NFE AF = 0.000206 (14/68018). AF 95% confidence interval is 0.000124. There are 0 homozygotes in GnomAd4. There are 4 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
BS2
High AC in GnomAd4 at 15 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PIK3CANM_006218.4 linkc.1130C>G p.Pro377Arg missense_variant Exon 6 of 21 ENST00000263967.4 NP_006209.2 P42336Q4LE51
PIK3CAXM_006713658.5 linkc.1130C>G p.Pro377Arg missense_variant Exon 6 of 21 XP_006713721.1 P42336Q4LE51

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PIK3CAENST00000263967.4 linkc.1130C>G p.Pro377Arg missense_variant Exon 6 of 21 2 NM_006218.4 ENSP00000263967.3 P42336

Frequencies

GnomAD3 genomes
AF:
0.0000986
AC:
15
AN:
152102
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
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:
0.000206
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000602
AC:
15
AN:
249268
AF XY:
0.0000518
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:
0.000124
Gnomad OTH exome
AF:
0.000165
GnomAD4 exome
AF:
0.000126
AC:
174
AN:
1384730
Hom.:
0
Cov.:
21
AF XY:
0.000107
AC XY:
74
AN XY:
693526
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32038
American (AMR)
AF:
0.00
AC:
0
AN:
44604
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25606
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39256
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84574
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53306
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5630
European-Non Finnish (NFE)
AF:
0.000160
AC:
167
AN:
1041988
Other (OTH)
AF:
0.000121
AC:
7
AN:
57728
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.460
Heterozygous variant carriers
0
9
18
28
37
46
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.0000985
AC:
15
AN:
152220
Hom.:
0
Cov.:
32
AF XY:
0.0000538
AC XY:
4
AN XY:
74406
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41528
American (AMR)
AF:
0.00
AC:
0
AN:
15298
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10584
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000206
AC:
14
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.502
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.000209
Hom.:
0
Bravo
AF:
0.0000756
TwinsUK
AF:
0.000809
AC:
3
ALSPAC
AF:
0.00
AC:
0
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000244
AC:
2
ExAC
AF:
0.0000662
AC:
8

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

PIK3CA-related disorder Uncertain:1
Nov 23, 2022
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The PIK3CA c.1130C>G variant is predicted to result in the amino acid substitution p.Pro377Arg. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.015% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/3-178922361-C-G). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Seborrheic keratosis;C0038356:Neoplasm of stomach;C0265552:Congenital macrodactylia;C0334082:Epidermal nevus;C0346153:Familial cancer of breast;C0684249:Lung carcinoma;C0699790:Carcinoma of colon;C0919267:Ovarian neoplasm;C1865285:Megalencephaly-capillary malformation-polymicrogyria syndrome;C2239176:Hepatocellular carcinoma;C2751313:CLAPO syndrome;C2752042:CLOVES syndrome;C3554518:Cowden syndrome 5 Uncertain:1
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cowden syndrome Uncertain:1
Dec 12, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with arginine, which is basic and polar, at codon 377 of the PIK3CA protein (p.Pro377Arg). This variant is present in population databases (rs113613074, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with PIK3CA-related conditions. ClinVar contains an entry for this variant (Variation ID: 403909). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt PIK3CA protein function with a positive predictive value of 95%. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.94
BayesDel_addAF
Uncertain
0.090
D
BayesDel_noAF
Pathogenic
0.21
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.69
D;.
Eigen
Uncertain
0.62
Eigen_PC
Uncertain
0.65
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Uncertain
0.97
D;D
M_CAP
Benign
0.053
D
MetaRNN
Uncertain
0.50
T;T
MetaSVM
Benign
-0.52
T
MutationAssessor
Uncertain
2.3
M;.
PhyloP100
7.5
PrimateAI
Pathogenic
0.88
D
PROVEAN
Benign
-1.6
N;.
REVEL
Uncertain
0.53
Sift
Benign
0.030
D;.
Sift4G
Benign
0.52
T;.
Polyphen
0.98
D;.
Vest4
0.90
MVP
0.80
MPC
1.4
ClinPred
0.21
T
GERP RS
5.6
Varity_R
0.56
gMVP
0.87
Mutation Taster
=50/50

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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: rs113613074; hg19: chr3-178922361; API