NM_000038.6:c.1723T>C

Variant names:

• chr5-112828952-T-C
• rs1391594497
• NM_000038.6:c.1723T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000038.6(APC):​c.1723T>C​(p.Cys575Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,459,718 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. C575S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.67
• Publications: 16 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_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 32 uncertain in NM_000038.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.907

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APC	NM_000038.6	c.1723T>C	p.Cys575Arg	missense_variant	Exon 14 of 16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.1723T>C	p.Cys575Arg	missense_variant	Exon 14 of 16	5	NM_000038.6	ENSP00000257430.4
ENSG00000258864	ENST00000520401.1	n.208T>C		non_coding_transcript_exon_variant	Exon 3 of 8	3		ENSP00000454861.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1459718 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 726276

African (AFR) AF: 0.00 AC: 0 AN: 33416

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26112

East Asian (EAS) AF: 0.00 AC: 0 AN: 39654

South Asian (SAS) AF: 0.00 AC: 0 AN: 86222

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53390

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1110120

Other (OTH) AF: 0.00 AC: 0 AN: 60320

GnomAD4 genome Cov.: 32

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:1

Jun 21, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (ExAC no frequency). 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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with APC-related disease. This sequence change replaces cysteine with arginine at codon 575 of the APC protein (p.Cys575Arg). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and arginine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Sep 07, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.C575R variant (also known as c.1723T>C), located in coding exon 13 of the APC gene, results from a T to C substitution at nucleotide position 1723. The cysteine at codon 575 is replaced by arginine, an amino acid with highly dissimilar properties. This amino acid position is highly 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 v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.23
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	.;D;D;T;T
Eigen	Pathogenic	0.68
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;.;D;D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Pathogenic	0.91	D;D;D;D;D
MetaSVM	Benign	-0.34	T
MutationAssessor	Benign	1.9	.;M;M;.;.
PhyloP100		7.7
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-10	D;D;D;D;.
REVEL	Pathogenic	0.72
Sift	Uncertain	0.0010	D;D;D;D;.
Sift4G	Uncertain	0.0020	D;D;D;D;D
Polyphen		0.98	.;D;D;.;.
Vest4		0.89, 0.93
MutPred		0.75		.;Gain of MoRF binding (P = 0.0071);Gain of MoRF binding (P = 0.0071);Gain of MoRF binding (P = 0.0071);.;
MVP		0.91
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.98
gMVP		0.94
Mutation Taster		=2/98	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: rs1391594497; hg19: chr5-112164649;