NM_006218.4:c.361A>G

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2PP2BP4

The NM_006218.4(PIK3CA):c.361A>G(p.Ile121Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000156 in 1,605,458 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. I121I) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

PIK3CA
NM_006218.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.94

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 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

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 hereditary breast carcinoma, vascular malformation, Cowden disease, Cowden syndrome 5, CLOVES syndrome, familial ovarian cancer, megalencephaly-capillary malformation-polymicrogyria syndrome, overgrowth syndrome and/or cerebral malformations due to abnormalities in MTOR pathway genes.

BP4

Computational evidence support a benign effect (MetaRNN=0.32660884).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PIK3CA	NM_006218.4 link	c.361A>G	p.Ile121Val	missense_variant	Exon 3 of 21	ENST00000263967.4	NP_006209.2	P42336Q4LE51
PIK3CA	XM_006713658.5 link	c.361A>G	p.Ile121Val	missense_variant	Exon 3 of 21		XP_006713721.1	P42336Q4LE51

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
PIK3CA	ENST00000263967.4 link	c.361A>G	p.Ile121Val	missense_variant	Exon 3 of 21	2	NM_006218.4	ENSP00000263967.3	P42336
PIK3CA	ENST00000643187.1 link	c.361A>G	p.Ile121Val	missense_variant	Exon 3 of 22			ENSP00000493507.1	A0A2R8Y2F6
PIK3CA	ENST00000675467.1 link	n.3168A>G		non_coding_transcript_exon_variant	Exon 2 of 20
PIK3CA	ENST00000675786.1 link	n.361A>G		non_coding_transcript_exon_variant	Exon 3 of 21			ENSP00000502323.1	A0A6Q8PGN9

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152140

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000160

AC:

AN:

249232

Hom.:

AF XY:

0.0000148

AC XY:

AN XY:

135228

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000354

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000138

AC:

AN:

1453318

Hom.:

Cov.:

AF XY:

0.0000152

AC XY:

AN XY:

723444

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000163

Gnomad4 OTH exome

AF:

0.0000333

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152140

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74318

show subpopulations

Gnomad4 AFR

AF:

0.0000482

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000901

Hom.:

Bravo

AF:

0.0000264

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000123

AC:

ExAC

AF:

0.0000248

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Cowden syndrome

Uncertain:1

Apr 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 121 of the PIK3CA protein (p.Ile121Val). This variant is present in population databases (rs371727887, gnomAD 0.006%). 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: 246688). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on PIK3CA protein function. 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

Benign

0.084

BayesDel_addAF

Benign

-0.088

BayesDel_noAF

Benign

-0.23

CADD

Benign

DANN

Benign

0.95

DEOGEN2

Uncertain

0.42

T;.

Eigen

Benign

0.12

Eigen_PC

Uncertain

0.24

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Uncertain

0.91

D;D

M_CAP

Benign

0.011

MetaRNN

Benign

0.33

T;T

MetaSVM

Benign

-0.97

MutationAssessor

Benign

2.0

M;.

PrimateAI

Uncertain

0.55

PROVEAN

Benign

-0.88

N;.

REVEL

Benign

0.26

Sift

Benign

0.055

T;.

Sift4G

Benign

0.11

T;.

Polyphen

0.23

B;.

Vest4

0.63

MVP

0.45

MPC

0.71

ClinPred

0.24

GERP RS

5.8

Varity_R

0.25

gMVP

0.59

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over