chr3-179203761-T-C

Position:

• chr3-179203761-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP2

The NM_006218.4(PIK3CA):​c.1031T>C​(p.Val344Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V344M) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PIK3CA NM_006218.4 missense
• Clinical Significance: Likely pathogenic no assertion criteria provided P:8
• Conservation: PhyloP100: 7.56

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a domain C2 PI3K-type (size 157) in uniprot entity PK3CA_HUMAN there are 6 pathogenic changes around while only 1 benign (86%) in NM_006218.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-179203760-G-A is described in Lovd as [Pathogenic].
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), PIK3CA. . Gene score misZ: 5.5986 (greater than the threshold 3.09). Trascript score misZ: 6.1406 (greater than threshold 3.09). The gene has 98 curated pathogenic missense variants (we use a threshold of 10). The gene has 13 curated benign missense variants. GenCC has associacion of the gene with hereditary breast carcinoma, vascular malformation, Cowden disease, Cowden syndrome 5, CLOVES syndrome, familial ovarian cancer, megalencephaly-capillary malformation-polymicrogyria syndrome, overgrowth syndrome and/or cerebral malformations due to abnormalities in MTOR pathway genes.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PIK3CA	NM_006218.4	c.1031T>C	p.Val344Ala	missense_variant	5/21	ENST00000263967.4	NP_006209.2
PIK3CA	XM_006713658.5	c.1031T>C	p.Val344Ala	missense_variant	5/21		XP_006713721.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PIK3CA	ENST00000263967.4	c.1031T>C	p.Val344Ala	missense_variant	5/21	2	NM_006218.4	ENSP00000263967.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:8

Revision: no assertion criteria provided

Submissions by phenotype

Glioblastoma Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

May 31, 2016

- -

Malignant neoplasm of body of uterus Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

May 31, 2016

- -

Breast neoplasm Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

May 31, 2016

- -

Non-Hodgkin lymphoma Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

May 31, 2016

- -

Neoplasm of uterine cervix Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

May 31, 2016

- -

Malignant melanoma of skin Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

May 31, 2016

- -

Neoplasm of the large intestine Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

May 31, 2016

- -

Squamous cell carcinoma of the head and neck Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

May 31, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.14
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.53	D;.
Eigen	Pathogenic	0.70
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Uncertain	0.092	D
MetaRNN	Uncertain	0.66	D;D
MetaSVM	Uncertain	-0.069	T
MutationAssessor	Uncertain	2.6	M;.
PrimateAI	Pathogenic	0.91	D
PROVEAN	Benign	-1.5	N;.
REVEL	Uncertain	0.52
Sift	Uncertain	0.0090	D;.
Sift4G	Uncertain	0.028	D;.
Polyphen		0.99	D;.
Vest4		0.74
MutPred		0.42		Gain of loop (P = 0.1069);Gain of loop (P = 0.1069);
MVP		0.76
MPC		2.0
ClinPred		0.95	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.51
gMVP		0.81

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

LitVar

Other links and lift over

dbSNP: rs1057519941; hg19: chr3-178921549; COSMIC: COSV55974473; COSMIC: COSV55974473;