NM_000038.6:c.2845A>T

Variant names:

• chr5-112838439-A-T
• rs587781348
• NM_000038.6:c.2845A>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000038.6(APC):​c.2845A>T​(p.Met949Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,252 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. 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. M949I) has been classified as Likely benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 1.28
• Publications: 2 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: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.06453887).

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.2845A>T	p.Met949Leu	missense	Exon 16 of 16	NP_000029.2
	APC	NM_001407446.1		c.2929A>T	p.Met977Leu	missense	Exon 16 of 16	NP_001394375.1
	APC	NM_001354896.2		c.2899A>T	p.Met967Leu	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.2845A>T	p.Met949Leu	missense	Exon 16 of 16	ENSP00000257430.4
	APC	ENST00000508376.6	TSL:1	c.2845A>T	p.Met949Leu	missense	Exon 17 of 17	ENSP00000427089.2
	APC	ENST00000502371.3	TSL:1	n.*1043A>T		non_coding_transcript_exon	Exon 12 of 12	ENSP00000484935.2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152252 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152252 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74390

African (AFR) AF: 0.00 AC: 0 AN: 41466

American (AMR) AF: 0.00 AC: 0 AN: 15284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5204

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68048

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:1

Jul 28, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals affected with APC-related conditions. 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. 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. ClinVar contains an entry for this variant (Variation ID: 537559). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces methionine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 949 of the APC protein (p.Met949Leu).

Classic or attenuated familial adenomatous polyposis Uncertain:1

Feb 22, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces methionine with leucine at codon 949 of the APC protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with APC-related disorders 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.

Hereditary cancer-predisposing syndrome Uncertain:1

Aug 15, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.M949L variant (also known as c.2845A>T), located in coding exon 15 of the APC gene, results from an A to T substitution at nucleotide position 2845. The methionine at codon 949 is replaced by leucine, an amino acid with highly similar properties. This amino acid position is not 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.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.081
BayesDel_addAF	Uncertain	0.018	T
BayesDel_noAF	Benign	-0.21
CADD	Benign	12
DANN	Benign	0.82
DEOGEN2	Uncertain	0.49	T
Eigen	Benign	-0.73
Eigen_PC	Benign	-0.52
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.78	T
M_CAP	Benign	0.025	D
MetaRNN	Benign	0.065	T
MetaSVM	Benign	-0.63	T
MutationAssessor	Benign	-0.59	N
PhyloP100		1.3
PrimateAI	Benign	0.36	T
PROVEAN	Benign	0.59	N
REVEL	Benign	0.20
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Polyphen		0.0	B
Vest4		0.29
MutPred		0.41		Loss of helix (P = 0.0041)
MVP		0.73
ClinPred		0.041	T
GERP RS		0.74
Varity_R		0.026
gMVP		0.22
Mutation Taster		=65/35	polymorphism

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: rs587781348; hg19: chr5-112174136;