5-112707370-C-T

Variant names:

• chr5-112707370-C-T
• rs1273083857
• NM_001407446.1:c.-348C>T

Variant summary

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

The NM_001407446.1(APC):​c.-348C>T variant causes a upstream gene change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000528 in 189,220 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000053 (0 hom.)
• Consequence: APC NM_001407446.1 upstream_gene
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -3.42
• Publications: 0 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

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 (BayesDel_noAF=-0.76).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APC	NM_001407446.1	c.-348C>T		upstream_gene_variant			NP_001394375.1
APC	NM_001407447.1	c.-531C>T		upstream_gene_variant			NP_001394376.1
APC	NM_001407448.1	c.-298C>T		upstream_gene_variant			NP_001394377.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000509732.6	c.-298C>T		upstream_gene_variant		4		ENSP00000426541.2
APC	ENST00000507379.6	c.-348C>T		upstream_gene_variant		2		ENSP00000423224.2
APC	ENST00000505350.2	n.-348C>T		upstream_gene_variant		3		ENSP00000481752.1
APC	ENST00000713636.1	n.-531C>T		upstream_gene_variant				ENSP00000518937.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000528 AC: 1 AN: 189220 Hom.: 0 AF XY: 0.0000104 AC XY: 1 AN XY: 96338

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 6830

American (AMR) AF: 0.00 AC: 0 AN: 7994

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 7124

East Asian (EAS) AF: 0.0000665 AC: 1 AN: 15042

South Asian (SAS) AF: 0.00 AC: 0 AN: 23990

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 6264

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 868

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 109272

Other (OTH) AF: 0.00 AC: 0 AN: 11836

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:1

Jan 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant occurs in a non-coding region of the APC gene. It does not change the encoded amino acid sequence of the APC protein. This variant is present in population databases (no rsID available, gnomAD 0.007%). 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: 469892). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.76
CADD	Benign	0.23
DANN	Benign	0.86
PhyloP100		-3.4
PromoterAI		-0.14	Neutral

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1273083857; hg19: chr5-112043067;