5-112838434-G-T

Variant names:

• chr5-112838434-G-T
• rs997271472
• NM_000038.6:c.2840G>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_000038.6(APC):​c.2840G>T​(p.Cys947Phe) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C947Y) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 4.88
• Publications: 5 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: G2P, Genomics England PanelApp
• familial adenomatous polyposis 1

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

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

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• APC-related attenuated familial adenomatous polyposis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Turcot syndrome with polyposis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Cenani-Lenz syndactyly syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000258864 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000038.6. 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
	APC	NM_000038.6	MANE Select	c.2840G>T	p.Cys947Phe	missense	Exon 16 of 16	NP_000029.2
	APC	NM_001407446.1		c.2924G>T	p.Cys975Phe	missense	Exon 16 of 16	NP_001394375.1
	APC	NM_001354896.2		c.2894G>T	p.Cys965Phe	missense	Exon 17 of 17	NP_001341825.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	APC	ENST00000257430.9	TSL:5 MANE Select	c.2840G>T	p.Cys947Phe	missense	Exon 16 of 16	ENSP00000257430.4
	APC	ENST00000508376.6	TSL:1	c.2840G>T	p.Cys947Phe	missense	Exon 17 of 17	ENSP00000427089.2
	APC	ENST00000502371.3	TSL:1	n.*1038G>T		non_coding_transcript_exon	Exon 12 of 12	ENSP00000484935.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Jun 07, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.C947F variant (also known as c.2840G>T), located in coding exon 15 of the APC gene, results from a G to T substitution at nucleotide position 2840. The cysteine at codon 947 is replaced by phenylalanine, an amino acid with highly dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, in silico predictors for this gene do not accurately predict pathogenicity. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Mar 06, 2024

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces cysteine with phenylalanine at codon 947 of the APC protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.

not specified Uncertain:1

Dec 22, 2017

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: The APC c.2840G>T (p.Cys947Phe) variant involves the alteration of a conserved nucleotide and 4/5 in silico tools predict a damaging outcome for this variant. However, these predictions have yet to be functionally assessed. This variant is absent in 245618 control chromosomes (gnomAD). The variant of interest has not, to our knowledge, been reported in affected individuals via publications and/or reputable databases/clinical diagnostic laboratories. Because of the absence of clinical information and the lack of functional studies, the variant is classified as a "Variant of Uncertain Significance (VUS)," until additional information becomes available.

Familial adenomatous polyposis 1 Uncertain:1

Jul 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces cysteine, which is neutral and slightly polar, with phenylalanine, which is neutral and non-polar, at codon 947 of the APC protein (p.Cys947Phe). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with APC-related conditions. ClinVar contains an entry for this variant (Variation ID: 469777). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt APC protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

not provided Uncertain:1

Nov 03, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.70	D
Eigen	Uncertain	0.66
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D
M_CAP	Uncertain	0.13	D
MetaRNN	Uncertain	0.71	D
MetaSVM	Uncertain	0.74	D
MutationAssessor	Uncertain	2.3	M
PhyloP100		4.9
PrimateAI	Uncertain	0.66	T
PROVEAN	Benign	-0.65	N
REVEL	Uncertain	0.57
Sift	Benign	0.062	T
Sift4G	Benign	0.40	T
Polyphen		1.0	D
Vest4		0.94
MutPred		0.32		Gain of helix (P = 0.0425)
MVP		0.98
ClinPred		0.59	D
GERP RS		5.8
Varity_R		0.29
gMVP		0.34
Mutation Taster		=19/81	disease causing

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: rs997271472; hg19: chr5-112174131;