5-112839129-T-A

Position:

• chr5-112839129-T-A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 1P and 4B. PP3 BS2

The NM_000038.6(APC):​c.3535T>A​(p.Tyr1179Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000137 in 1,461,780 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. Y1179C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000014 (0 hom.)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 7.24

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]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.775
• BS2: High AC in GnomAdExome4 at 20 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APC	NM_000038.6	c.3535T>A	p.Tyr1179Asn	missense_variant	16/16	ENST00000257430.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APC	ENST00000257430.9	c.3535T>A	p.Tyr1179Asn	missense_variant	16/16	5	NM_000038.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000400 AC: 1 AN: 249950 Hom.: 0 AF XY: 0.00000738 AC XY: 1 AN XY: 135498

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: 0.00000884

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000137 AC: 20 AN: 1461780 Hom.: 0 Cov.: 33 AF XY: 0.0000110 AC XY: 8 AN XY: 727188

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000171

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.00 AC: 0

ExAC AF: 0.00000824 AC: 1

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	Invitae	Nov 24, 2023	This sequence change replaces tyrosine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 1179 of the APC protein (p.Tyr1179Asn). This variant is present in population databases (rs751249843, gnomAD 0.0009%). This missense change has been observed in individual(s) with clinical features of Lynch syndrome (PMID: 25980754). ClinVar contains an entry for this variant (Variation ID: 411482). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Jun 23, 2023	- -

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 10, 2023	The p.Y1179N variant (also known as c.3535T>A), located in coding exon 15 of the APC gene, results from a T to A substitution at nucleotide position 3535. The tyrosine at codon 1179 is replaced by asparagine, an amino acid with dissimilar properties. This alteration was identified in a cohort of 1260 individuals undergoing panel testing for Lynch syndrome due to having a diagnosis of a Lynch-associated cancer and/or polyps (Yurgelun MB et al. Gastroenterology. 2015 Sep;149(3):604-13.e20). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 22, 2019	This missense variant replaces tyrosine with asparagine at codon 1179 of the APC protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has been reported in 1 individual affected with a Lynch syndrome-associated tumor and/or polyps (PMID: 25980754). This variant has been identified in 1/249950 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 24, 2017

This variant is denoted APC c.3535T>A at the cDNA level, p.Tyr1179Asn (Y1179N) at the protein level, and results in the change of a Tyrosine to an Asparagine (TAT>AAT). This variant has been observed in at least one individual with a Lynch syndrome-associated tumor and/or polyps (Yurgelun 2015). APC Tyr1179Asn was not observed at a significant allele frequency in large population cohorts (Lek 2016). Since Tyrosine and Asparagine differ in some properties, this is considered a semi-conservative amino acid substitution. APC Tyr1179Asn occurs at a position that is conserved across species and is not located in a known functional domain. In silico analyses are inconsistent regarding the effect this variant may have on protein structure and function. Based on currently available evidence, it is unclear whether APC Tyr1179Asn 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	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.77	D;D;D
Eigen	Uncertain	0.53
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	.;D;D
M_CAP	Uncertain	0.21	D
MetaRNN	Pathogenic	0.78	D;D;D
MetaSVM	Uncertain	0.73	D
MutationAssessor	Benign	1.0	L;L;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-1.3	N;N;N
REVEL	Pathogenic	0.83
Sift	Pathogenic	0.0	D;D;D
Sift4G	Benign	0.24	T;T;T
Polyphen		0.96	D;D;.
Vest4		0.84
MutPred		0.57		Loss of phosphorylation at Y1179 (P = 0.0346);Loss of phosphorylation at Y1179 (P = 0.0346);Loss of phosphorylation at Y1179 (P = 0.0346);
MVP		0.98
ClinPred		0.75	D
GERP RS		5.8
Varity_R		0.58
gMVP		0.67

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: rs751249843; hg19: chr5-112174826;