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NM_000314.8:c.763_773del
p.Val255ProfsTer39 · PTEN
0%
complete
Final classification
Likely Pathogenic
PVS1PM2
PTEN
c.763_773del
p.Val255ProfsTer39
frameshift · exon 7

PTEN is a tumor suppressor gene that encodes a phosphatase converting the lipid messenger PIP3 back to PIP2 at the cell membrane, thereby restraining the AKT/mTOR signaling pathway that drives cell growth, proliferation, and survival. It is one of the most frequently mutated genes across many types of human cancer, and its loss promotes unchecked cell growth, survival, and genomic instability, partly through impaired DNA repair. Germline loss-of-function variants in PTEN cause Cowden syndrome, an inherited cancer predisposition disorder associated with elevated risk of breast and thyroid cancer.

This variant

By truncating PTEN before the C-terminal region, c.763_773del is predicted to abolish the phosphatase activity that normally converts PIP3 back to PIP2 to restrain AKT/mTOR signaling, the loss-of-function mechanism that underlies Cowden syndrome predisposition to breast and thyroid cancer.

Transcript
NM_000314.8
HGVS · transcript:coding
NM_000314.8:c.763_773del
GRCh38
chr10:87957980 AGTAGAGTTCTT>A
GRCh37
chr10:89717737 AGTAGAGTTCTT>A
Likely Pathogenic: PVS1 (very strong) plus PM2 (supporting) satisfy Rule20 of the ClinGen PTEN Expert Panel, requiring one very strong and one supporting criterion.
Classification rationale
PVS1PM2 Likely Pathogenic
PTEN c.763_773del frameshift · exon 7

PVS1 very strong: the 11-bp deletion creates frameshift p.(Val255ProfsTer39) with its premature stop upstream of the PTEN NMD boundary p.D375 (c.1121), predicting loss of function via NMD. PM2 supporting: the variant is absent (AF=0) from gnomAD v2.1, v4.1, and gnomAD-Canada, below the PTEN Expert Panel's 0.001% overall allele-frequency threshold.

PVS1 + PM2 → Likely Pathogenic
LYFE Sciences is an AI system, and it can make mistakes. Criteria may be applied incorrectly, sources may be misread, and a confident-looking classification can still be wrong. Double-check every criterion and its underlying evidence before relying on any call.
Gene diagram · NM_000314.8 · variants mapped to exon structure
PTEN NM_000314.8
Fetching transcript structure from UCSC…
Applied criteria · 2 applied · 15 assessed
MetEvidence satisfies this criterion.
Not metEvaluated against available evidence; threshold not reached.
Not assessedApplies in principle, but no evidence was found to evaluate it.
N/ADoesn't apply to this variant type.
Applied · 2
Strength Supporting Moderate Strong Very strong
PVS1 very strong Pathogenic
Met (very strong): frameshift c.763_773del creates a stop at codon 293 (p.(Val255ProfsTer39)), 5' of PTEN's NMD cutoff p.D375 (c.1121), so NMD is predicted and PVS1 applies per the PTEN decision tree.
VariantValidator/Mutalyzer normalization: NM_000314.8:c.763_773del (11-nt deletion in exon 7) -> NP_000305.3:p.(Val255ProfsTer39); wild-type PTEN is 403 aa and the predicted mutant translation terminates at residue 293, so the premature stop is at protein position 293 (~c.877-879), well 5' of p.D375 (residue 375, c.1121).ClinGen PTEN EP cspec v3.2 (doc 135637575) lists PVS1 as applicable with rule 'Use PTEN PVS1 decision tree' and default strength Pathogenic Very Strong; framework_mode is vcep (VCEP spec governs over generic ACMG).PTEN EP specification text (PVS1 instructions): 'PVS1 applies to variants predicted to result in nonsense-mediated decay (NMD); the predicted NMD cutoff for PTEN occurs at c.1121 (p.D375).'
PM2 supporting Pathogenic
Met (supporting): the variant is absent from gnomAD v2.1, v4.1, and gnomAD-Canada (AF 0), meeting the PTEN EP PM2 threshold of <0.001% with no subpopulation alleles.
PTEN ClinGen Expert Panel (cspec v3.2) PM2 rule (Supporting only): 'Absent in population: Databases present at <0.00001 (0.001%) allele frequency in gnomAD or another large sequenced population. If multiple alleles are present within any subpopulation, allele frequency in that subpopulation must be <0.00002 (0.002%).'gnomAD v2.1 lookup (10-89717737-AGTAGAGTTCTT-A) returned the variant as absent (AF 0).gnomAD v4.1 lookup (chr10-87957980-AGTAGAGTTCTT-A) returned the variant as absent (AF 0).
Assessed · not applied · 10 not met · 5 not assessed
Pathogenic
PS2 Not assessed: no confirmed de novo observation (maternity and paternity both confirmed, disease, no family history) exists, which PTEN VCEP PS2 requires.
PS3 Not assessed: no functional assay of this variant exists; the Mighell 2018 PTEN saturation assay scores only missense variants, not this c.763_773del frameshift.
PS4 Not met: no probands or case-control data exist for c.763_773del (ClinVar, gnomAD, literature all empty); phenotype specificity score 0 fails the >=1 supporting threshold.
PM1 Not met: PM1 residue 255 falls outside the PTEN VCEP catalytic motifs that define PM1 (90-94, 123-130, 166-168), and no VCEP domain table or hotspot includes it.
PM6 Not assessed: no presumed de novo occurrence (parents not tested, disease present, no family history) is documented, which PM6 requires.
PP1 Not assessed: no segregation observations exist; PP1 requires co-segregation in multiple affected family members with 3-4 meioses (supporting) and none are reported.
PP5 Not met: ClinVar has no entry for c.763_773del, so no exact-variant expert-panel Pathogenic/Likely pathogenic classification exists to support PP5.
Benign
BA1 Not met: gnomAD filtering AF is 0 (absent from gnomAD v2.1, v4.1, and gnomAD-Canada), far below the PTEN EP BA1 threshold of >0.00056.
BS1 Not met: the variant is absent from population databases (AF 0), below the PTEN EP BS1_Supporting floor of 0.0000043 filtering AF.
BS2 Not met: no homozygous observations exist; c.763_773del is absent from gnomAD v2.1, v4.1, and gnomAD-Canada (0 homozygotes).
BS3 Not met: no functional study shows preserved PTEN activity, and the truncating frameshift p.(Val255ProfsTer39) removes residues 255-403 of the 403-amino-acid protein.
BS4 Not assessed: no affected-family-member genotyping exists; BS4 requires demonstrated lack of segregation in affected members of one or more families, not merely absent data.
BP2 Not met: c.763_773del is absent from ClinVar and gnomAD with zero documented observations, so it is not observed in trans with a P/LP PTEN variant or in three cis/unknown-phase observations.
BP5 Not met: no case documents an alternate highly penetrant molecular cause with no PTEN phenotype overlap, and PTEN VCEP BP5 requires at least two such cases.
BP6 Not met: ClinVar has no entry for c.763_773del, so no exact-variant expert-panel Benign/Likely benign classification exists to support BP6.
N/A · 11 PS1 · PM3 · PM4 · PM5 · PP2 · PP3 · PP4 · BP1 · BP3 · BP4 · BP7
Research & evidence
Population frequency · supports pathogenic
gnomAD v4.1 screenshot
gnomAD v4.1
gnomAD v2.1 screenshot
gnomAD v2.1
v4.1
Absent from gnomAD v4.1.
v2.1
Absent from gnomAD v2.1.
🇨🇦 CA
Absent from gnomAD-Canada v1.0.
Allele frequency by ancestry
three datasets · side by side
gnomAD v4.1
Absent · 0 / ?
0 hom
Not observed in any ancestry group.
gnomAD v2.1
Absent · 0 / ?
0 hom
Not observed in any ancestry group.
gnomAD Canada 🇨🇦
Absent · 0 / ?
0 hom
Not observed in any ancestry group.
ClinVar screenshot
ClinVar
This variant is absent from ClinVar.
SpliceAI screenshot
In silico
SpliceAI predicts no significant splice impact for this variant (max delta score = 0.02).
Functional / OncoKB screenshot
Functional Likely Oncogenic
OncoKB identified variant-specific curated literature and context relevant to functional review; biological-effect context: Likely Loss-of-function; curated oncogenicity label: Likely Oncogenic.
OncoKB ↗
COSMIC screenshot
COSMIC
Cancer hotspots screenshot
Cancer hotspots
Somatic evidence Not in COSMIC / hotspots
COSMIC
This variant does not lie in a statistically significant hotspot. This variant has not previously been reported in somatic cancers (COSMIC).
Hotspots
This variant does not lie in a statistically significant hotspot.
Sources & reference links
9Sources
CSpec VCEP
ClinVar
gnomAD v2.1
gnomAD v4.1
gnomAD-Canada
SpliceAI
OncoKB
COSMIC
Cancer hotspots