3-179166549-C-T

Variant names:

• chr3-179166549-C-T
• rs2699905
• NM_006218.4:c.-77+17946C>T

Variant summary

Our verdict is Benign. The variant received -12 ACMG points: 0P and 12B. BP4_Strong BA1

The NM_006218.4(PIK3CA):​c.-77+17946C>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.185 in 152,194 control chromosomes in the GnomAD database, including 2,944 homozygotes. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.19 (2944 hom., cov: 33)
• Consequence: PIK3CA NM_006218.4 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.113
• Publications: 22 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: 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

ACMG classification

Our verdict: Benign. The variant received -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.69).
• BA1: GnomAd4 highest subpopulation (NFE) allele frequency at 95% confidence interval = 0.244 is higher than 0.05.

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIK3CA	NM_006218.4	MANE Select	c.-77+17946C>T		intron	N/A	NP_006209.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIK3CA	ENST00000263967.4	TSL:2 MANE Select	c.-77+17946C>T		intron	N/A	ENSP00000263967.3
	PIK3CA	ENST00000643187.1		c.-77+17946C>T		intron	N/A	ENSP00000493507.1
	PIK3CA	ENST00000468036.1	TSL:3	c.-77+16833C>T		intron	N/A	ENSP00000417479.1

Frequencies

GnomAD3 genomes AF: 0.185 AC: 28193 AN: 152076 Hom.: 2943 Cov.: 33

Gnomad AFR AF: 0.0984

Gnomad AMI AF: 0.313

Gnomad AMR AF: 0.163

Gnomad ASJ AF: 0.218

Gnomad EAS AF: 0.0677

Gnomad SAS AF: 0.168

Gnomad FIN AF: 0.210

Gnomad MID AF: 0.136

Gnomad NFE AF: 0.247

Gnomad OTH AF: 0.176

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.185 AC: 28195 AN: 152194 Hom.: 2944 Cov.: 33 AF XY: 0.181 AC XY: 13484 AN XY: 74412

African (AFR) AF: 0.0983 AC: 4084 AN: 41556

American (AMR) AF: 0.162 AC: 2484 AN: 15292

Ashkenazi Jewish (ASJ) AF: 0.218 AC: 756 AN: 3470

East Asian (EAS) AF: 0.0678 AC: 352 AN: 5188

South Asian (SAS) AF: 0.169 AC: 814 AN: 4830

European-Finnish (FIN) AF: 0.210 AC: 2226 AN: 10590

Middle Eastern (MID) AF: 0.129 AC: 38 AN: 294

European-Non Finnish (NFE) AF: 0.247 AC: 16781 AN: 67950

Other (OTH) AF: 0.177 AC: 375 AN: 2114

Alfa AF: 0.224 Hom.: 4150

Bravo AF: 0.177

Asia WGS AF: 0.113 AC: 394 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.69
CADD	Benign	6.7
DANN	Benign	0.67
PhyloP100		-0.11
Mutation Taster		=100/0	polymorphism (auto)

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: rs2699905; hg19: chr3-178884337;