rs867262025

Variant names:

• chr3-179221146-G-A
• rs867262025
• NM_006218.4:c.2176G>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PS4 PS2 PP2 PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The c.2176G>A (NM_006218.4) variant in PIK3CA is a missense variant predicted to cause substitution of (p.Glu726Lys). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). PIK3CA, in which the variant was identified, is defined by the ClinGen Brain Malformations Expert Panel as a gene that has a low rate of benign missense variation and where pathogenic missense variants are a common mechanism of disease (PP2). The prevalence of the variant in affected individuals is significantly increased compared with the prevalence in controls (PS4_VS; identified in at least 15 individuals with a clinical diagnosis of megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome; (MPPH) or megalencephaly-capillary malformation-polymicrogyria syndrome; (MCAP), it has been shown to significantly increase phosphorylation levels in patient cell lines (PMID:28566443), and is in at least 15 tumor samples in the literature and COSMIC (PMID:22729224, PMID:28941273, PMID:24497998 )). This variant has been confirmed de novo and has been identified with variable allelic fractions consistent with a post-zygotic event (PS2_Strong; PMIDs: 22729224, 22729224). In summary, this variant meets the criteria to be classified as Pathogenic for mosaic autosomal dominant overgrowth with or without cerebral malformations due to abnormalities in MTOR-pathway genes based on the ACMG/AMP criteria applied, as specified by the ClinGen Brain Malformations Expert Panel: PM2_P, PP2, PS4_VS, PS2; 14 points (VCEP specifications version 1; Approved: 1/31/2021) LINK:https://erepo.genome.network/evrepo/ui/classification/CA16602910/MONDO:0016054/018

• Frequency: Genomes: not found (cov: 32)
• Consequence: PIK3CA NM_006218.4 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:10 O:2
• Conservation: PhyloP100: 9.60
• Publications: 200 publications found

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: Labcorp Genetics (formerly Invitae), Ambry Genetics, 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)
• hereditary breast carcinoma

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
• familial ovarian cancer

  Inheritance: Unknown Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PS2: For more information check the summary or visit ClinGen Evidence Repository.
• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PP2: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006218.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIK3CA	NM_006218.4	MANE Select	c.2176G>A	p.Glu726Lys	missense	Exon 14 of 21	NP_006209.2	P42336

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIK3CA	ENST00000263967.4	TSL:2 MANE Select	c.2176G>A	p.Glu726Lys	missense	Exon 14 of 21	ENSP00000263967.3	P42336
	PIK3CA	ENST00000955190.1		c.2206G>A	p.Glu736Lys	missense	Exon 14 of 21	ENSP00000625249.1
	PIK3CA	ENST00000876545.1		c.2176G>A	p.Glu726Lys	missense	Exon 15 of 22	ENSP00000546604.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
3	-	-	not provided (3)
2	-	-	Megalencephaly-capillary malformation-polymicrogyria syndrome (2)
2	-	-	PIK3CA related overgrowth syndrome (2)
1	-	-	Cowden syndrome (1)
1	-	-	Inborn genetic diseases (1)
1	-	-	Overgrowth syndrome and/or cerebral malformations due to abnormalities in MTOR pathway genes (1)
-	-	-	Diffuse pediatric-type high-grade glioma, H3-wildtype and IDH-wildtype (1)
-	-	-	Dysembryoplastic neuroepithelial tumor (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.65
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Uncertain	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.24	T
Eigen	Uncertain	0.36
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D
M_CAP	Benign	0.059	D
MetaRNN	Uncertain	0.56	D
MetaSVM	Benign	-0.46	T
MutationAssessor	Benign	0.64	N
PhyloP100		9.6
PrimateAI	Pathogenic	0.89	D
PROVEAN	Benign	0.25	N
REVEL	Uncertain	0.44
Sift	Benign	0.81	T
Sift4G	Benign	1.0	T
Polyphen		0.87	P
Vest4		0.74
MutPred		0.34		Gain of MoRF binding (P = 0.0033)
MVP		0.95
MPC		2.1
ClinPred		0.65	D
GERP RS		5.7
Varity_R		0.50
gMVP		0.56
Mutation Taster		=23/77	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs867262025; hg19: chr3-178938934; COSMIC: COSV55875460;