NM_000038.6:c.221-5T>C

Variant names:

• chr5-112767184-T-C
• rs1057524155
• NM_000038.6:c.221-5T>C

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_000038.6(APC):​c.221-5T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,010 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: APC NM_000038.6 splice_region, intron
• Scores: Splicing: ADA: 0.01043
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:5
• Conservation: PhyloP100: 0.933
• 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 -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.46).
• BP6: Variant 5-112767184-T-C is Benign according to our data. Variant chr5-112767184-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 391594.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APC	NM_000038.6	c.221-5T>C		splice_region_variant, intron_variant	Intron 3 of 15	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.221-5T>C		splice_region_variant, intron_variant	Intron 3 of 15	5	NM_000038.6	ENSP00000257430.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459010 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726118

African (AFR) AF: 0.00 AC: 0 AN: 33440

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86198

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53400

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 9.01e-7 AC: 1 AN: 1109420

Other (OTH) AF: 0.00 AC: 0 AN: 60296

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Apr 30, 2021

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes a T to C nucleotide substitution at the -5 position of intron 3 of the APC gene. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has not been identified 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. -

Jul 18, 2023

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

not specified Benign:2

Dec 05, 2016

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Apr 16, 2025

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

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: APC c.221-5T>C alters a non-conserved nucleotide located at a position not widely known to affect splicing. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 6.2e-07 in 1604400 control chromosomes (gnomAD v4.1). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.221-5T>C in individuals affected with Familial Adenomatous Polyposis and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 391594). Based on the evidence outlined above, the variant was classified as likely benign. -

Familial adenomatous polyposis 1 Benign:2

Sep 25, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 22, 2024

Myriad Genetics, Inc.

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign. This variant is intronic and is not expected to impact mRNA splicing. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.46
CADD	Benign	11
DANN	Benign	0.82
PhyloP100		0.93

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.010
dbscSNV1_RF	Benign	0.032
SpliceAI score (max)		0.060		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: rs1057524155; hg19: chr5-112102881; COSMIC: COSV105854775;