NM_006218.4:c.2651A>G

Variant summary

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

The NM_006218.4(PIK3CA):​c.2651A>G​(p.Lys884Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,609,658 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

PIK3CA
NM_006218.4 missense

Scores

1
9
9

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 8.84

Publications

0 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: Uncertain_significance. The variant received 5 ACMG points.

PM1
In a domain PI3K/PI4K catalytic (size 286) in uniprot entity PK3CA_HUMAN there are 26 pathogenic changes around while only 1 benign (96%) 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
PIK3CANM_006218.4 linkc.2651A>G p.Lys884Arg missense_variant Exon 18 of 21 ENST00000263967.4 NP_006209.2 P42336Q4LE51
PIK3CAXM_006713658.5 linkc.2651A>G p.Lys884Arg missense_variant Exon 18 of 21 XP_006713721.1 P42336Q4LE51

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PIK3CAENST00000263967.4 linkc.2651A>G p.Lys884Arg missense_variant Exon 18 of 21 2 NM_006218.4 ENSP00000263967.3 P42336

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152170
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1457488
Hom.:
0
Cov.:
30
AF XY:
0.00000276
AC XY:
2
AN XY:
724968
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33250
American (AMR)
AF:
0.00
AC:
0
AN:
43516
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25942
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39572
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85410
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53330
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5740
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1110544
Other (OTH)
AF:
0.00
AC:
0
AN:
60184
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152170
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74334
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000329
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Mar 18, 2019
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The PIK3CA c.2651A>G; p.Lys884Arg variant (rs1395235750), to our knowledge, is not reported in the medical literature but is reported in ClinVar (Variation ID: 526637). This variant is absent from general population databases (Exome Variant Server, Genome Aggregation Database), indicating it is not a common polymorphism. The lysine at codon 884 is highly conserved but computational analyses (SIFT, PolyPhen-2) predict that this variant is tolerated. Due to limited information, the clinical significance of the p.Lys884Arg variant is uncertain at this time. -

Inborn genetic diseases Uncertain:1
May 11, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.2651A>G (p.K884R) alteration is located in exon 18 (coding exon 17) of the PIK3CA gene. This alteration results from a A to G substitution at nucleotide position 2651, causing the lysine (K) at amino acid position 884 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Aug 22, 2018
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cowden syndrome Uncertain:1
Jan 18, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. 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. ClinVar contains an entry for this variant (Variation ID: 526637). This variant has not been reported in the literature in individuals affected with PIK3CA-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 884 of the PIK3CA protein (p.Lys884Arg). -

Seborrheic keratosis;C0024623:Gastric cancer;C0242379:Lung cancer;C0265552:Congenital macrodactylia;C0334082:Epidermal nevus;C0346153:Familial cancer of breast;C0346629:Colorectal cancer;C0919267:Ovarian neoplasm;C1865285:Megalencephaly-capillary malformation-polymicrogyria syndrome;C2239176:Hepatocellular carcinoma;C2751313:CLAPO syndrome;C2752042:CLOVES syndrome;C3554518:Cowden syndrome 5 Uncertain:1
Aug 13, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.070
BayesDel_addAF
Uncertain
0.14
D
BayesDel_noAF
Uncertain
-0.040
CADD
Uncertain
23
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.45
T;.
Eigen
Benign
0.077
Eigen_PC
Uncertain
0.27
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.90
D;D
M_CAP
Benign
0.047
D
MetaRNN
Uncertain
0.54
D;D
MetaSVM
Benign
-0.58
T
MutationAssessor
Benign
1.2
L;.
PhyloP100
8.8
PrimateAI
Uncertain
0.73
T
PROVEAN
Benign
-1.2
N;.
REVEL
Uncertain
0.35
Sift
Benign
0.20
T;.
Sift4G
Benign
0.44
T;.
Polyphen
0.041
B;.
Vest4
0.51
MutPred
0.55
Loss of ubiquitination at K884 (P = 0.0218);Loss of ubiquitination at K884 (P = 0.0218);
MVP
0.90
MPC
1.3
ClinPred
0.77
D
GERP RS
5.5
Varity_R
0.20
gMVP
0.74
Mutation Taster
=46/54
disease causing

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

Other links and lift over

dbSNP: rs1395235750; hg19: chr3-178947215; API