5-112780903-G-C

Variant names:

• chr5-112780903-G-C
• rs1060503295
• NM_000038.6:c.645G>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_000038.6(APC):​c.645G>C​(p.Gln215His) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. 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. Q215R) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: APC NM_000038.6 missense, splice_region
• Scores: Splicing: ADA: 0.9996
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.99
• Publications: 1 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: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000038.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	APC	NM_000038.6	MANE Select	c.645G>C	p.Gln215His	missense splice_region	Exon 6 of 16	NP_000029.2
	APC	NM_001407446.1		c.675G>C	p.Gln225His	missense splice_region	Exon 5 of 16	NP_001394375.1
	APC	NM_001354896.2		c.645G>C	p.Gln215His	missense splice_region	Exon 6 of 17	NP_001341825.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	APC	ENST00000257430.9	TSL:5 MANE Select	c.645G>C	p.Gln215His	missense splice_region	Exon 6 of 16	ENSP00000257430.4
	APC	ENST00000508376.6	TSL:1	c.645G>C	p.Gln215His	missense splice_region	Exon 7 of 17	ENSP00000427089.2
	APC	ENST00000502371.3	TSL:1	n.645G>C		splice_region non_coding_transcript_exon	Exon 5 of 12	ENSP00000484935.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:1

May 13, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamine with histidine at codon 215 of the APC protein (p.Gln215His). The glutamine residue is highly conserved and there is a small physicochemical difference between glutamine and histidine. It also falls at the last nucleotide of exon 6 of the APC coding sequence. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with an APC-related disease. ClinVar contains an entry for this variant (Variation ID: 411420). Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). Nucleotide substitutions within the consensus splice site are relatively common causes of aberrant splicing (PMID: 17576681, 9536098) but according to multiple splice site algorithms this particular variant is not predicted to significantly affect splicing. These predictions have not been confirmed by published functional studies. In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.29
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	34
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Benign	0.80	T
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.75	D
MetaSVM	Pathogenic	0.85	D
MutationAssessor	Uncertain	2.7	M
PhyloP100		9.0
PrimateAI	Uncertain	0.66	T
PROVEAN	Uncertain	-3.5	D
REVEL	Pathogenic	0.75
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0030	D
Polyphen		0.99	D
Vest4		0.83
MutPred		0.19		Loss of ubiquitination at K212 (P = 0.0618)
MVP		0.96
ClinPred		0.99	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.74
gMVP		0.59
Mutation Taster		=5/95	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.89
SpliceAI score (max)		0.020		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: rs1060503295; hg19: chr5-112116600;