chr3-179199698-A-C

Position:

• chr3-179199698-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_006218.4(PIK3CA):​c.361A>C​(p.Ile121Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. I121I) has been classified as Benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PIK3CA NM_006218.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.94

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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). GenCC has associacion of 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.361A>C	p.Ile121Leu	missense_variant	3/21	ENST00000263967.4	NP_006209.2
PIK3CA	XM_006713658.5	c.361A>C	p.Ile121Leu	missense_variant	3/21		XP_006713721.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PIK3CA	ENST00000263967.4	c.361A>C	p.Ile121Leu	missense_variant	3/21	2	NM_006218.4	ENSP00000263967	P1
PIK3CA	ENST00000643187.1	c.361A>C	p.Ile121Leu	missense_variant	3/22			ENSP00000493507
PIK3CA	ENST00000675467.1	n.3168A>C		non_coding_transcript_exon_variant	2/20
PIK3CA	ENST00000675786.1	c.361A>C	p.Ile121Leu	missense_variant, NMD_transcript_variant	3/21			ENSP00000502323

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 04, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.37
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.080
CADD	Benign	22
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.51	D;.
Eigen	Uncertain	0.33
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.95	D;D
M_CAP	Benign	0.042	D
MetaRNN	Uncertain	0.53	D;D
MetaSVM	Benign	-0.87	T
MutationAssessor	Benign	2.0	M;.
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.64	T
PROVEAN	Benign	-1.9	N;.
REVEL	Benign	0.21
Sift	Uncertain	0.0040	D;.
Sift4G	Uncertain	0.010	D;.
Polyphen		0.67	P;.
Vest4		0.79
MutPred		0.47		Loss of helix (P = 0.0167);Loss of helix (P = 0.0167);
MVP		0.60
MPC		0.95
ClinPred		0.83	D
GERP RS		5.8
Varity_R		0.73
gMVP		0.74

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.10		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr3-178917486;