NM_000038.6:c.4348C>T

Variant names:

• chr5-112839942-C-T
• rs121913332
• NM_000038.6:c.4348C>T
• APC p.Arg1450*

GermlineCancer (beta)

Variant summary

Our verdict is Pathogenic.

>+14 Pathogenic

-7

-6

-1

0

+5

+6

+9

+10

BenignB

Likely BenignLB

UncertainVUS

Likely PathogenicLP

PathogenicP

The variant received 22 classification points (ACGS-UK Somatic Oncogenicity v2025). O1_StrongO2_Very_StrongO3_ModerateO4_ModerateO7_StrongO9_Moderate

The NM_000038.6(APC):c.4348C>T (p.Arg1450*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. This is a loss-of-function variant that does not trigger NMD. The gene APC is a tumor suppressor gene (CancerMine: 215 TSG, 264 oncogene, 89 driver citations). The gene APC is a known oncogene (CancerMine: 215 TSG, 264 oncogene, 89 driver citations). The gene APC is a cancer driver gene (CancerMine: 215 TSG, 264 oncogene, 89 driver citations). The variant is absent from the gnomAD population database at sites with sufficient sequencing coverage. In-silico predictor (BayesDel (noAF)) classifies this variant as likely damaging/oncogenic. Splicing prediction tools (SpliceAI) predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic/Likely Pathogenic (★★). The variant position is a cancer hotspot (cancerhotspots.org): 29 samples carry this exact amino acid change out of 58 samples with a variant at this residue. The variant has been observed in cBioPortal in 1403 samples across 77 studies and 40 cancer types; somatic enrichment level: MODERATE (Observed in many cases across multiple studies/cancer contexts.). This exact variant is curated in the UniProt human variants database as Uncertain Significance; it is also listed as a COSMIC curated somatic variant.

• Frequency: Genomes: not found (cov: 32)
• Consequence: APC NM_000038.6 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:11 O:2
• Conservation: PhyloP100: 3.21
• Publications: 1 publications found

Genes affected

APC (HGNC:583): (APC regulator of Wnt signaling pathway) This gene encodes a tumor suppressor protein that acts as an antagonist of the Wnt signaling pathway. It is also involved in other processes including cell migration and adhesion, transcriptional activation, and apoptosis. Defects in this gene cause familial adenomatous polyposis (FAP), an autosomal dominant pre-malignant disease that usually progresses to malignancy. Mutations in the APC gene have been found to occur in most colorectal cancers, where disease-associated mutations tend to be clustered in a small region designated the mutation cluster region (MCR) and result in a truncated protein product. [provided by RefSeq, Jun 2022]

APC Gene-Disease associations (from GenCC):

• classic or attenuated familial adenomatous polyposis

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• desmoid tumor

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P
• familial adenomatous polyposis 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
• gastric adenocarcinoma and proximal polyposis of the stomach

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Orphanet, Ambry Genetics
• sarcoma

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• Cenani-Lenz syndactyly syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000258864 (HGNC:):

Classification according to ACGS-UK Somatic Oncogenicity v2025

Specifications for APC are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Classification was made for transcript:

Our verdict: Pathogenic. The variant received 22 points.

Apply	Criterion Code & Title / Strength	Strength	Rationale / Clinical Context
	O1Established oncogenic variant		ClinVar oncogenic/SCI T1 (multiple submitters, ★★) — Strong (O1); ClinVar oncogenic/SCI T1 (single/no review, ★0–1) — Moderate (O1); TSG gene: ClinVar germline P/LP ★★+ — Moderate (O1); O1 contributing sources (4.0 pts): ClinVar (somatic oncogenic/LO (★★)), ClinVar germline P/LP in TSG (★★)
	O2Null variant in tumour suppressor gene		Non-NMD frameshift: ≥20 downstream pathogenic — O2 very strong (+8); Use caution in the presence of multiple transcripts; Gene confirmed as TSG in CancerMine (TSG: 215 citations, oncogene: 264 citations, driver: 89 citations).; Frameshift/stop-gained. NMD predicted: false. LoF mechanism: true. Downstream pathogenic count: 696.
	O3Absent or very rare in population		Absent or extremely rare in gnomAD (AC ≤ 2) — O3 moderate; GnomAD: AF = absent, AC = 0 — absent/extremely rare (O3 moderate [+2])
	O4Enriched in somatic variant database		Enriched in cBioPortal (pre-computed score ≥ 2.0) — Moderate (O4); cBioPortal: samples=1403 | studies=77 | cancer types=40 | level=MODERATE | points=2.0 | reason: Observed in many cases across multiple studies/cancer contexts.
	O7Mutational hotspot or critical domain		Strong hotspot (cancerhotspots.org): >50 total samples, ≥10 same AA change; Note: exclude MSK/TCGA-derived samples from cancerhotspots count to avoid double-counting with O4; cancerhotspots.org: total samples at AA position = 58, same AA change = 29; Exclude MSK/TCGA-derived samples from count to avoid double-counting with O4; UniProt domain: 0 pathogenic, 0 benign.; ±8 AA neighbourhood: 0 pathogenic, 0 benign; Variant does not impact splicing — splice-hotspot path not applicable
	O9Protein length change in non-repeat region		Truncating variant in final exon of oncogene — predicted GOF (O9 moderate); Truncating variant in final exon of oncogene — predicted to escape NMD and result in GOF

Variant Effect in Transcripts

Automated classification analysis was done for transcript: NM_000038.6. You can select a different transcript below to see updated classification assignments.

RefSeq Transcripts

Sel.	Gene / Transcript	Tags	HGVSc / HGVSp	Effect	Exon rank	Protein / UniProt
	APC NM_000038.6	MANE Select	c.4348C>T p.Arg1450*	stop_gained	Exon 16 of 16	Prot: NP_000029.2
	APC NM_001407446.1		c.4432C>T p.Arg1478*	stop_gained	Exon 16 of 16	Prot: NP_001394375.1
	APC NM_001354896.2		c.4402C>T p.Arg1468*	stop_gained	Exon 17 of 17	Prot: NP_001341825.1 UniProt:

APC NM_000038.6

MANE Select

HGVSc / HGVSpc.4348C>Tp.Arg1450*

Exon rankExon 16 of 16

stop_gained

Prot: NP_000029.2

APC NM_001407446.1

HGVSc / HGVSpc.4432C>Tp.Arg1478*

Exon rankExon 16 of 16

stop_gained

Prot: NP_001394375.1

APC NM_001354896.2

HGVSc / HGVSpc.4402C>Tp.Arg1468*

Exon rankExon 17 of 17

stop_gained

Prot: NP_001341825.1UniProt: R4GMU6

Ensembl Transcripts

Sel.	Gene / Transcript	Tags	HGVSc / HGVSp	Effect	Exon rank	Protein / UniProt
	APC ENST00000257430.9	TSL:5MANE Select	c.4348C>T p.Arg1450*	stop_gained	Exon 16 of 16	Prot: ENSP00000257430.4 UniProt:
	APC ENST00000508376.6	TSL:1	c.4348C>T p.Arg1450*	stop_gained	Exon 17 of 17	Prot: ENSP00000427089.2 UniProt:
	APC ENST00000508624.5	TSL:1	n.*3670C>T	3_prime_UTR	Exon 17 of 17	Prot: ENSP00000424265.1 UniProt:

APC ENST00000257430.9

TSL:5MANE Select

HGVSc / HGVSpc.4348C>Tp.Arg1450*

Exon rankExon 16 of 16

stop_gained

Prot: ENSP00000257430.4UniProt: P25054-1

APC ENST00000508376.6

TSL:1

HGVSc / HGVSpc.4348C>Tp.Arg1450*

Exon rankExon 17 of 17

stop_gained

Prot: ENSP00000427089.2UniProt: P25054-1

APC ENST00000508624.5

TSL:1

HGVSc / HGVSpn.*3670C>T

Exon rankExon 17 of 17

3_prime_UTR

Prot: ENSP00000424265.1UniProt: E7EMH9

Frequencies

Allele frequencies (AF), counts (AC/AN), homozygotes and coverage

Common (AF > 0.05 / Hom > 5)

Rare (AF ≤ 0.0001 / Hom ≤ 1)

Source / population	AF	AC	Hom	AN	Coverage
Global population databases 4 sources Large-scale international reference populations
GnomAD3 genomes	AF:	AC:	Hom:	AN:	Cov:32
GnomAD2 exomes	AF: 0.00	AC:0	Hom:	AN:251172	Cov:
GnomAD4 exome	AF:	AC:	Hom:	AN:	Cov:34
GnomAD4 genome	AF:	AC:	Hom:	AN:	Cov:32

Showing 4 sources

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
6	-	-	not provided (6)
3	-	-	Familial adenomatous polyposis 1 (3)
1	-	-	Familial multiple polyposis syndrome (1)
1	-	-	Hereditary cancer-predisposing syndrome (1)
-	-	-	APC-Associated Polyposis Disorders (1)
-	-	-	Neoplasm (1)

Computational Scores

Algorithm	Calibrated pred.	Score	Prediction
AlphaGenome AVI	Pathogenic	36
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Uncertain	0.90	D
GPN-Star LLR	N/A	-9.0
GPN-Star score	N/A	9.0
Mutation Taster	N/A	0/200	disease causing (ClinVar)
PhyloP100	Benign	3.2
RBP_binding_hub_radar	N/A	0.0
RBP_regulation_power_radar	N/A	1.7

Showing 14 of 14 scores

Splicing Scores

Algorithm	Calibrated pred.	Score	Prediction
Pangolin (max)	Benign	0.0
SpliceAI score (max)	Benign	0.0	Details are displayed if max score is > 0.2

Showing 2 of 2 scores

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

MaveDB functional evidence

MaveDB is a public repository of laboratory assays that test the effect of thousands of variants at once — treat this as supporting research data and interpret it with great caution; it is not a clinical classification.

No MaveDB functional evidence found for this variant.

Other links and lift over

dbSNP: rs121913332;

hg19: chr5-112175639;

COSMIC: COSV57321313;

COSMIC: COSV57321313;

ACMG debug oncogenicity

ACGS debug oncogenicity

ACMG debug germline

Submit to ClinVar