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Gene

PIK3CA

phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha

Summary

Cytogenetic location
3q26.32
Coordinates
Chromosome 3: 179,148,357–179,240,093 (GRCh38)
Exons
21 exons across 91.7 kb
Protein
1,068 amino acids
Also known as
PI3K
MANE Select transcript
ENST00000263967.4NM_006218.4
Locus type
gene with protein product
  • Very high
  • Confident
  • Low
  • Very low

Reference genomeGRCh38

Positions on gene and variant pages follow this choice, in this browser.

Curated reports relevant to this gene

No Genome Test report reads PIK3CA yet. The test sequences your whole genome, so your data includes it all the same.

How PIK3CA is laid out

  • Coding sequence
  • Untranslated region
  • Intron
  • Direction of transcription
  • Known disease-causing sites
  • Stretches short reads find hard
Chromosome 3, with a bracket where PIK3CA sits. PIK3CA and 12 genes near it on chromosome 3, from 178,694,225 to 179,694,224.Chromosome 33q26.32p26.3p26.2p26.1p25.3p25.2p25.1p24.3p24.2p24.1p23p22.3p22.2p22.1p21.33p21.32p21.31p21.2p21.1p14.3p14.2p14.1p13p12.3p12.2p12.1p11.2p11.1q11.1q11.2q12.1q12.2q12.3q13.11q13.12q13.13q13.2q13.31q13.32q13.33q21.1q21.2q21.3q22.1q22.2q22.3q23q24q25.1q25.2q25.31q25.32q25.33q26.1q26.2q26.31q26.32q26.33q27.1q27.2q27.3q28q29178.8 Mb179 Mb179.2 Mb179.4 Mb179.6 MbKCNMB2: 178,272,932–178,847,008, forward strandKCNMB2: 178,419,123–178,843,300, forward strandZMAT3: 178,958,103–179,072,323, reverse strandZMAT3PIK3CA: 179,148,357–179,240,093, forward strandPIK3CAKCNMB3: 179,236,690–179,267,002, reverse strandKCNMB3ZNF639: 179,322,856–179,338,583, forward strandZNF639MFN1: 179,346,952–179,396,566, forward strandMFN1GNB4: 179,396,088–179,451,647, reverse strandGNB4ACTL6A: 179,562,886–179,588,462, forward strandACTL6AMRPL47: 179,571,524–179,604,663, reverse strandMRPL47NDUFB5: 179,604,690–179,632,777, forward strandNDUFB5: 179,604,807–179,784,179, forward strandUSP13: 179,652,730–179,804,368, forward strandUSP13Diagram of PIK3CA: 21 exons on the forward strand of chromosome 3Exon 2: 19 known disease-causing sitesExon 3: 2 known disease-causing sitesExon 5: 6 known disease-causing sitesExon 6: 4 known disease-causing sitesExon 8: 12 known disease-causing sitesExon 10: 8 known disease-causing sitesExon 12: 1 known disease-causing siteExon 14: 2 known disease-causing sitesExon 19: 2 known disease-causing sitesExon 20: 2 known disease-causing sitesExon 21: 14 known disease-causing sitesExon 1: 179,148,357–179,148,603, 247 basesExon 2: 179,198,750–179,199,177, 428 basesExon 3: 179,199,690–179,199,899, 210 basesExon 4: 179,201,290–179,201,540, 251 basesExon 5: 179,203,544–179,203,789, 246 basesExon 6: 179,204,503–179,204,588, 86 basesExon 7: 179,209,595–179,209,700, 106 basesExon 8: 179,210,186–179,210,338, 153 basesExon 9: 179,210,431–179,210,565, 135 basesExon 10: 179,218,210–179,218,334, 125 basesExon 11: 179,219,196–179,219,277, 82 basesExon 12: 179,219,571–179,219,735, 165 basesExon 13: 179,219,949–179,220,052, 104 basesExon 14: 179,220,986–179,221,157, 172 basesExon 15: 179,224,081–179,224,187, 107 basesExon 16: 179,224,700–179,224,821, 122 basesExon 17: 179,225,962–179,226,040, 79 basesExon 18: 179,229,272–179,229,442, 171 basesExon 19: 179,230,004–179,230,121, 118 basesExon 20: 179,230,225–179,230,376, 152 basesExon 21: 179,234,094–179,240,093, 6,000 bases15101520215′3′

Exons of the gene's MANE Select transcript (release v1.5), from NCBI and EMBL-EBI, on the GRCh38 reference genome.

Chromosome bands from UCSC's GRCh38 ideogram (2022-10-29).

Nearby genes from Ensembl release 116, on GRCh38.

Exons make up 9.3 kb of the gene's 91.7 kb; 3,207 of those bases code for the protein.

How a genome test reads PIK3CA

73

positions in PIK3CA where ClinVar classes a change as pathogenic or likely pathogenic

11 of them (15%) fall in regions short reads find hard.

  • Low mappability (11 sites)Regions where 100 bp or 250 bp reads cannot be placed uniquely.
  • Segmental duplications (11 sites)Copies of at least 1 kb sharing at least 90% identity with another part of the genome (paralogues, pseudogenes); reads may align to the wrong copy.

A whole genome covers all 91.7 kb of PIK3CA, introns included, not only the 9.3 kb of exons.

Where this comes from

  • HGNC: the gene's symbol, name, other symbols and location.
  • MANE Select v1.5, from NCBI and EMBL-EBI: the transcript, its exons and coding sequence.
  • ClinVar and the GIAB stratifications: known disease-causing sites, and the regions short reads find hard.
  • The Human Phenotype Ontology, release 2026-09-01: the traits linked to the gene. Find out more at hpo.jax.org.
  • Data release 2026.10.16-c6eea6bf.

Cite this page

APA

Dante Labs. (n.d.). PIK3CA gene: phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha. Retrieved 17 October 2026, from https://dantelabs.com/genes/pik3ca

Vancouver

Dante Labs. PIK3CA gene: phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha [Internet]. [cited 17 October 2026]. Available from: https://dantelabs.com/genes/pik3ca

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