3-179199737-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 1P and 7B. PP2BP4_ModerateBS1_SupportingBS2

The NM_006218.4(PIK3CA):c.400C>T(p.Pro134Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000868 in 1,612,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 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. P134T) has been classified as Uncertain significance.

Frequency

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

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

PIK3CA
NM_006218.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.54

Publications

6 publications found

Variant links:

COSMIC-nc: COSV55945791

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_benign. The variant received -6 ACMG points.

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=0.15101793).

BS1

Variant frequency is greater than expected in population amr. GnomAdExome4 allele frequency = 0.0000089 (13/1460866) while in subpopulation AMR AF = 0.000268 (12/44722). AF 95% confidence interval is 0.000154. There are 0 homozygotes in GnomAdExome4. There are 8 alleles in the male GnomAdExome4 subpopulation. Median coverage is 30. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High AC in GnomAdExome4 at 13 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PIK3CA	NM_006218.4 link	c.400C>T	p.Pro134Ser	missense_variant	Exon 3 of 21	ENST00000263967.4	NP_006209.2
PIK3CA	XM_006713658.5 link	c.400C>T	p.Pro134Ser	missense_variant	Exon 3 of 21		XP_006713721.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
PIK3CA	ENST00000263967.4 link	c.400C>T	p.Pro134Ser	missense_variant	Exon 3 of 21	2	NM_006218.4	ENSP00000263967.3
PIK3CA	ENST00000643187.1 link	c.400C>T	p.Pro134Ser	missense_variant	Exon 3 of 22			ENSP00000493507.1
PIK3CA	ENST00000675467.1 link	n.3207C>T		non_coding_transcript_exon_variant	Exon 2 of 20
PIK3CA	ENST00000675786.1 link	n.400C>T		non_coding_transcript_exon_variant	Exon 3 of 21			ENSP00000502323.1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152016

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000361

AC:

AN:

249444

AF XY:

0.0000369

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000232

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000883

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000890

AC:

AN:

1460866

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

726758

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33446

American (AMR)

AF:

0.000268

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26112

East Asian (EAS)

AF:

0.00

AC:

AN:

39596

South Asian (SAS)

AF:

0.00

AC:

AN:

86234

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53398

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

9.00e-7

AC:

AN:

1111232

Other (OTH)

AF:

0.00

AC:

AN:

60362

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.479

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.00000658

AC:

AN:

152016

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74258

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41388

American (AMR)

AF:

0.0000655

AC:

AN:

15268

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5202

South Asian (SAS)

AF:

0.00

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10584

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67972

Other (OTH)

AF:

0.00

AC:

AN:

2084

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.0000166

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Cowden syndrome

Uncertain:1

Jun 03, 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 serine, which is neutral and polar, at codon 134 of the PIK3CA protein (p.Pro134Ser). This variant is present in population databases (rs750545881, gnomAD 0.03%). 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: 456546). 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

0.11

BayesDel_addAF

Benign

-0.37

BayesDel_noAF

Benign

-0.48

CADD

Benign

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.66

D;.

Eigen

Benign

-0.13

Eigen_PC

Benign

0.065

FATHMM_MKL

Uncertain

0.93

LIST_S2

Uncertain

0.93

D;D

M_CAP

Benign

0.010

MetaRNN

Benign

0.15

T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.5

L;.

PhyloP100

2.5

PrimateAI

Uncertain

0.68

PROVEAN

Uncertain

-2.6

D;.

REVEL

Benign

0.057

Sift

Benign

0.043

D;.

Sift4G

Benign

0.29

T;.

Vest4

0.29

ClinPred

0.12

GERP RS

5.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

2.7

Varity_R

0.42

gMVP

0.59

Mutation Taster

=61/39

polymorphism

(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.

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