chr3-179203761-T-C

Variant names:

• chr3-179203761-T-C
• rs1057519941
• NM_006218.4:c.1031T>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 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 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 rank	MANE	Protein	UniProt
PIK3CA	NM_006218.4	c.1031T>C	p.Val344Ala	missense_variant	Exon 5 of 21	ENST00000263967.4	NP_006209.2
PIK3CA	XM_006713658.5	c.1031T>C	p.Val344Ala	missense_variant	Exon 5 of 21		XP_006713721.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PIK3CA	ENST00000263967.4	c.1031T>C	p.Val344Ala	missense_variant	Exon 5 of 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

May 31, 2016

Database of Curated Mutations (DoCM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Malignant neoplasm of body of uterus Pathogenic:1

May 31, 2016

Database of Curated Mutations (DoCM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Breast neoplasm Pathogenic:1

May 31, 2016

Database of Curated Mutations (DoCM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Non-Hodgkin lymphoma Pathogenic:1

May 31, 2016

Database of Curated Mutations (DoCM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Neoplasm of uterine cervix Pathogenic:1

May 31, 2016

Database of Curated Mutations (DoCM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Malignant melanoma of skin Pathogenic:1

May 31, 2016

Database of Curated Mutations (DoCM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Neoplasm of the large intestine Pathogenic:1

May 31, 2016

Database of Curated Mutations (DoCM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Squamous cell carcinoma of the head and neck Pathogenic:1

May 31, 2016

Database of Curated Mutations (DoCM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

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;