chr5-112840494-C-G

Position:

• chr5-112840494-C-G

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4 BS2

The NM_000038.6(APC):​c.4900C>G​(p.Pro1634Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000684 in 1,461,868 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 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. P1634L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 3.91

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]

ENSG00000258864 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -5 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.2667017).
• BS2: High AC in GnomAdExome4 at 10 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC	NM_000038.6	c.4900C>G	p.Pro1634Ala	missense_variant	16/16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.4900C>G	p.Pro1634Ala	missense_variant	16/16	5	NM_000038.6	ENSP00000257430.4
ENSG00000258864	ENST00000520401.1	n.228+11522C>G		intron_variant		3		ENSP00000454861.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251204 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135750

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461868 Hom.: 0 Cov.: 66 AF XY: 0.00000550 AC XY: 4 AN XY: 727238

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Dec 22, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 08, 2023	This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 1634 of the APC protein (p.Pro1634Ala). This variant is present in population databases (rs587779795, 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: 127300). 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. 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. -

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Dec 05, 2023	This missense variant replaces proline with alanine at codon 1634 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 been identified in 1/251204 chromosomes 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jul 26, 2023	The p.P1634A variant (also known as c.4900C>G), located in coding exon 15 of the APC gene, results from a C to G substitution at nucleotide position 4900. The proline at codon 1634 is replaced by alanine, an amino acid with highly similar 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Dec 18, 2017

This variant is denoted APC c.4900C>G at the cDNA level, p.Pro1634Ala (P1634A) at the protein level, and results in the change of a Proline to an Alanine (CCG>GCG). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. APC Pro1634Ala was not observed at a significant allele frequency in large population cohorts (Lek 2016). Since Proline and Alanine differ in some properties, this is considered a semi-conservative amino acid substitution. APC Pro1634Ala is located within the 20 amino acid repeat beta-catenin down-regulating domain and the SAMP repeats/axin binding domain (Azzopardi 2008). In-silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function. Based on currently available evidence, it is unclear whether APC Pro1634Ala is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.070
BayesDel_addAF	Uncertain	0.083	D
BayesDel_noAF	Benign	-0.12
CADD	Benign	19
DANN	Benign	0.93
DEOGEN2	Benign	0.39	T;T
Eigen	Benign	-0.041
Eigen_PC	Benign	0.18
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.94	.;D
M_CAP	Benign	0.033	D
MetaRNN	Benign	0.27	T;T
MetaSVM	Uncertain	-0.23	T
MutationAssessor	Benign	0.34	N;N
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	0.030	N;N
REVEL	Uncertain	0.32
Sift	Benign	0.11	T;T
Sift4G	Benign	0.81	T;T
Polyphen		0.13	B;B
Vest4		0.45
MutPred		0.43		Gain of catalytic residue at P1634 (P = 0.0088);Gain of catalytic residue at P1634 (P = 0.0088);
MVP		0.89
ClinPred		0.17	T
GERP RS		5.6
Varity_R		0.045
gMVP		0.45

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

Publications

LitVar

Other links and lift over

dbSNP: rs587779795; hg19: chr5-112176191;