3-179221050-G-A

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_006218.4(PIK3CA):c.2080G>A(p.Ala694Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000132 in 152,086 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. A694V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Consequence

PIK3CA
NM_006218.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.60

Publications

3 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: Uncertain_significance. The variant received 5 ACMG points.

PM1

In a domain PIK helical (size 177) in uniprot entity PK3CA_HUMAN there are 18 pathogenic changes around while only 0 benign (100%) 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PIK3CA	NM_006218.4 link	c.2080G>A	p.Ala694Thr	missense_variant	Exon 14 of 21	ENST00000263967.4	NP_006209.2	P42336Q4LE51
PIK3CA	XM_006713658.5 link	c.2080G>A	p.Ala694Thr	missense_variant	Exon 14 of 21		XP_006713721.1	P42336Q4LE51

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PIK3CA	ENST00000263967.4 link	c.2080G>A	p.Ala694Thr	missense_variant	Exon 14 of 21	2	NM_006218.4	ENSP00000263967.3		P42336

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152086

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.0000132

AC:

AN:

152086

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74280

show subpopulations

African (AFR)

AF:

0.0000483

AC:

AN:

41406

American (AMR)

AF:

0.00

AC:

AN:

15260

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10602

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68008

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Cowden syndrome

Uncertain:1

Jan 27, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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. 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. This variant has not been reported in the literature in individuals affected with PIK3CA-related conditions. This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 694 of the PIK3CA protein (p.Ala694Thr). This variant is not present in population databases (gnomAD no frequency). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.71

BayesDel_addAF

Uncertain

0.15

BayesDel_noAF

Uncertain

-0.020

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.83

D;.

Eigen

Uncertain

0.50

Eigen_PC

Uncertain

0.60

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.97

D;D

M_CAP

Benign

0.032

MetaRNN

Uncertain

0.65

D;D

MetaSVM

Benign

-0.65

MutationAssessor

Benign

1.3

L;.

PhyloP100

9.6

PrimateAI

Pathogenic

0.84

PROVEAN

Benign

-2.3

N;.

REVEL

Uncertain

0.31

Sift

Uncertain

0.0030

D;.

Sift4G

Uncertain

0.0050

D;.

Polyphen

0.61

P;.

Vest4

0.57

MutPred

0.70

Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);

MVP

0.70

MPC

2.0

ClinPred

0.87

GERP RS

5.4

Varity_R

0.67

gMVP

0.41

Mutation Taster

=38/62

disease causing

(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

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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