3-179198938-G-A

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM2PP2PP3_ModeratePP5_Moderate

The NM_006218.4(PIK3CA):c.113G>A(p.Arg38His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,459,198 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R38C) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

PIK3CA
NM_006218.4 missense

Scores

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1O:1

Conservation

PhyloP100: 9.54

Publications

87 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

PIK3CA links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PM1

In a domain PI3K-ABD (size 89) in uniprot entity PK3CA_HUMAN there are 9 pathogenic changes around while only 2 benign (82%) 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.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.845

PP5

Variant 3-179198938-G-A is Pathogenic according to our data. Variant chr3-179198938-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 376492.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PIK3CA	NM_006218.4 link	c.113G>A	p.Arg38His	missense_variant	Exon 2 of 21	ENST00000263967.4	NP_006209.2	P42336Q4LE51
PIK3CA	XM_006713658.5 link	c.113G>A	p.Arg38His	missense_variant	Exon 2 of 21		XP_006713721.1	P42336Q4LE51

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PIK3CA	ENST00000263967.4 link	c.113G>A	p.Arg38His	missense_variant	Exon 2 of 21	2	NM_006218.4	ENSP00000263967.3		P42336

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000402

AC:

AN:

248664

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000292

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000206

AC:

AN:

1459198

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726004

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33392

American (AMR)

AF:

0.0000224

AC:

AN:

44578

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26082

East Asian (EAS)

AF:

0.00

AC:

AN:

39662

South Asian (SAS)

AF:

0.00

AC:

AN:

85988

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53406

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1110018

Other (OTH)

AF:

0.00

AC:

AN:

60306

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.458

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000828

AC:

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1Other:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Overgrowth syndrome and/or cerebral malformations due to abnormalities in MTOR pathway genes

Pathogenic:1

Apr 07, 2024

Molecular Genetics, Royal Melbourne Hospital

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change in PIK3CA is predicted to replace arginine with histidine at codon 38, p.(Arg38His). The arginine residue is highly conserved (100 vertebrates, Multiz Alignments), and is located in adaptor binding domain (PI3K ABD) a region, amino acids 31-108, that is defined as a mutational hotspot. There is a small physicochemical difference between arginine and histidine. PIK3CA , in which the variant was identified, is a gene that has a low rate of benign missense variation and where pathogenic missense variants are a common mechanism of disease (gnomAD v2.1). The highest population minor allele frequency in the population database gnomAD v4.0 is 0.0002% (2/1,110,018 alleles) in the European (non-Finnish) population. This variant has been detected in at least one individual with polymicrogyria (Melbourne Health Pathology) and has been reported as a somatic event in at least 40 tumour samples (COSMIC ID: COSV55879949). In vitro functional studies assessing kinase activity (with limited assay validation) demonstrate a gain of function effect for the variant which is weaker than well-established pathogenic gain of function variants (PMID: 15930273, 16339315, 17376864). Computational evidence predicts a deleterious effect for the missense substitution (REVEL = 0.654). Based on the classification scheme RMH Modified ACMG/AMP Guidelines v1.6.1, this variant is classified as LIKELY PATHOGENIC. Following criteria are met: PS4_Moderate, PM1_Supporting, PM2_Supporting, PP2, PP3, PS3_Supporting. -

Neoplasm

Other:1

Mar 04, 2025

Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital

Significance:-

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.96

BayesDel_addAF

Pathogenic

0.22

BayesDel_noAF

Uncertain

0.070

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.86

D;.;.

Eigen

Pathogenic

0.81

Eigen_PC

Pathogenic

0.80

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.99

D;D;D

M_CAP

Uncertain

0.14

MetaRNN

Pathogenic

0.84

D;D;D

MetaSVM

Uncertain

0.029

MutationAssessor

Uncertain

2.3

M;.;.

PhyloP100

9.5

PrimateAI

Pathogenic

0.79

PROVEAN

Uncertain

-3.4

D;.;D

REVEL

Pathogenic

0.65

Sift

Uncertain

0.0090

D;.;D

Sift4G

Uncertain

0.026

D;.;D

Polyphen

1.0

D;.;.

Vest4

0.69

MutPred

0.69

Loss of sheet (P = 0.1501);Loss of sheet (P = 0.1501);Loss of sheet (P = 0.1501);

MVP

0.80

MPC

2.1

ClinPred

0.97

GERP RS

5.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.92

gMVP

0.80

Mutation Taster

=67/33

disease causing (ClinVar)

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

3-179198938-G-A

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over