rs1064793535

chr5-112767318-C-Achr5-112767318-C-Gchr5-112767318-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000038.6(APC):c.350C>A(p.Ser117Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.000000684 in 1,461,842 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. S117S) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: APC NM_000038.6 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 6.25

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 Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-112767318-C-A is Pathogenic according to our data. Variant chr5-112767318-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 418932.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APC	NM_000038.6	c.350C>A	p.Ser117Ter	stop_gained	4/16	ENST00000257430.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APC	ENST00000257430.9	c.350C>A	p.Ser117Ter	stop_gained	4/16	5	NM_000038.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461842 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727218

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 1 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 27, 2024	This sequence change creates a premature translational stop signal (p.Ser117*) in the APC gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in APC are known to be pathogenic (PMID: 17963004, 20685668). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with APC-related disease (PMID: 11960572, 23159591). ClinVar contains an entry for this variant (Variation ID: 418932). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Apr 25, 2023	This variant is considered pathogenic. This variant creates a termination codon and is predicted to result in premature protein truncation. -

Familial multiple polyposis syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

Jan 10, 2022

Variant summary: APC c.350C>A (p.Ser117X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 251476 control chromosomes (gnomAD). c.350C>A has been reported in the literature in individuals affected with Familial Adenomatous Polyposis (examples: Wu_2001, Kerr_2013 and Findlen_2021). These data indicate that the variant is associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Oct 18, 2017

This pathogenic variant is denoted APC c.350C>A at the cDNA level and p.Ser117Ter (S117X) at the protein level. The substitution creates a nonsense variant, which changes a Serine to a premature stop codon (TCA>TAA), and is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. This variant has been reported in association with attenuated Familial Adenomatous Polyposis (Kerr 2013) and is considered pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 16, 2021

The p.S117* pathogenic mutation (also known as c.350C>A), located in coding exon 3 of the APC gene, results from a C to A substitution at nucleotide position 350. This changes the amino acid from a serine to a stop codon within coding exon 3. This mutation has been detected in multiple individuals with familial adenomatous polyposis (FAP) (Wu G et al. Genet. Test., 2001;5:281-90; Kerr SE et al. J Mol Diagn, 2013 Jan;15:31-43; Gutierrez Sanchez LH et al. Gastrointest Endosc, 2018 Mar;87:648-656.e3). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.65
Cadd	Pathogenic	37
Dann	Uncertain	0.99
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	A;A;A
Vest4		0.94, 0.87
GERP RS		5.5

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: rs1064793535; hg19: chr5-112103015; COSMIC: COSV57362856; COSMIC: COSV57362856;