vabase

PIK3CA C420R

c.1258T>CNM_006218.33-179210192-T-C
PI3K-AKT gain of function transition Cancer hotspot Absent from gnomAD ClinVar: Pathogenic AlphaMissense: likely pathogenic LM

Reports 1 in LM

ISSVA entityAllele fractionSources
LM LEC line (monoallelic in vitro) (Blesinger); 0.22% (Li 2023, CVA199)

Position in PIK3CA 16 catalogued variants in this gene

PI3K-ABD (16–105)PI3K-ABDPI3K-RBD (187–289)PI3K-RBDC2 PI3K-type (330–487)C2 PI3K-typePIK helical (517–694)PIK helicalPI3K/PI4K catalytic (765–1051)PI3K/PI4K ca…11068 aaR88QE109delE110delN345KC420RP447_L455delE542KE545AE545GE545KQ546KQ546RM1043IH1047LH1047R*1069Pheext*4

Pathway and targeted therapy

Variant in the PI3K-AKT pathway. Repurposed drugs already used in the clinic for this pathway: alpelisib (PI3Kα inhibitor), sirolimus (mTOR inhibitor).

Open and recent trials (4 in vascular / lymphatic anomalies for alpelisib)

Primary sources 2

  1. Genomic profiling informs diagnoses and treatment in vascular anomalies.
    Li D, Sheppard SE, March ME, Battig MR, Surrey LF, Srinivasan AS, Matsuoka LS, Tian L, Wang F, Seiler C, Dayneka J, Borst AJ, Matos MC, Paulissen SM, Krishnamurthy G, Nriagu B, Sikder T, Casey M, Williams L, Rangu S, O'Connor N, Thomas A, Pinto E, Hou C, Nguyen K, Pellegrino da Silva R, Chehimi SN, Kao C, Biroc L, Britt AD, Queenan M, Reid JR, Napoli JA, Low DM, Vatsky S, Treat J, Smith CL, Cahill AM, Snyder KM, Adams DM, Dori Y, Hakonarson H. · Nat Med · 2023
  2. PIK3CA mutations are specifically localized to lymphatic endothelial cells of lymphatic malformations.
    Blesinger H, Kaulfuß S, Aung T, Schwoch S, Prantl L, Rößler J, Wilting J, Becker J. · PLoS One · 2018

Mentioned in 297 publications indexed by Europe PMC.

Annotations refreshed 2026-10-09 from Europe PMC, ClinVar, ClinicalTrials.gov, gnomAD, and Genome Nexus. Coordinates handled per assembly (gnomAD GRCh38, Genome Nexus GRCh37).