rs1554069530

Positions:

• chr5-112766354-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000038.6(APC):​c.164T>C​(p.Ile55Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,458,944 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: APC NM_000038.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.95

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC	NM_000038.6	c.164T>C	p.Ile55Thr	missense_variant	3/16	ENST00000257430.9	NP_000029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APC	ENST00000257430.9	c.164T>C	p.Ile55Thr	missense_variant	3/16	5	NM_000038.6	ENSP00000257430	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1458944 Hom.: 0 Cov.: 28 AF XY: 0.00000138 AC XY: 1 AN XY: 726054

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: 9.01e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial adenomatous polyposis 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 27, 2017

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. 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"). This variant has not been reported in the literature in individuals with APC-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces isoleucine with threonine at codon 55 of the APC protein (p.Ile55Thr). The isoleucine residue is highly conserved and there is a moderate physicochemical difference between isoleucine and threonine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.26
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.38	T;.;D;D;T
Eigen	Uncertain	0.56
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.89	D;D;.;D;D
M_CAP	Uncertain	0.11	D
MetaRNN	Uncertain	0.50	T;T;T;T;T
MetaSVM	Uncertain	0.29	D
MutationAssessor	Benign	1.6	.;.;L;L;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-3.4	D;N;N;N;D
REVEL	Benign	0.29
Sift	Uncertain	0.0030	D;D;D;D;D
Sift4G	Uncertain	0.0040	D;D;D;D;D
Polyphen		1.0	.;.;D;D;.
Vest4		0.90, 0.93
MutPred		0.23		Gain of loop (P = 0.024);.;Gain of loop (P = 0.024);Gain of loop (P = 0.024);Gain of loop (P = 0.024);
MVP		0.95
ClinPred		0.97	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.85
gMVP		0.41

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: rs1554069530; hg19: chr5-112102051;