19-1462084-A-G

Position:

• chr19-1462084-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_005883.3(APC2):​c.1760A>G​(p.Tyr587Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,762 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 Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: APC2 NM_005883.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.75

Genes affected

APC2 (HGNC:24036): (APC regulator of WNT signaling pathway 2) This gene encodes a strongly conserved protein that has an N-terminal coiled-coil domain followed by an armadillo domain, five 20-amino acid repeats, and two SAMP domains. This protein promotes the assembly of a multiprotein complex that recruits and phosphorylates the Wnt effector beta-catenin and targets beta-catenin for ubiquitylation and proteasomal degradation. This protein therefore plays a role in the reduction of cytoplasmic levels of beta-catenin which in turn reduces activation of Wnt target genes that play a pivotal role in the pathogenesis of various human cancers. The protein encoded by this gene is closely related to the adenomatous polyposis coli (APC) tumor-suppressor protein and has similar tumor-suppressor effects. This gene also plays a role in actin assembly, cell-cell adhesion, and microtubule network formation through its interaction with cytoskeletal proteins. This gene has its highest expression in the central nervous system and is involved in brain development through cytoskeletal regulation in neurons. Alternative splicing produces multiple transcript variants encoding distinct isoforms. [provided by RefSeq, May 2017]

C19orf25 (HGNC:26711): (chromosome 19 open reading frame 25)

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.862

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APC2	NM_005883.3	c.1760A>G	p.Tyr587Cys	missense_variant	14/15	ENST00000590469.6	NP_005874.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APC2	ENST00000590469.6	c.1760A>G	p.Tyr587Cys	missense_variant	14/15	1	NM_005883.3	ENSP00000467073	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250340 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135760

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000886

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460762 Hom.: 0 Cov.: 39 AF XY: 0.00000138 AC XY: 1 AN XY: 726664

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Dec 14, 2023

Variant summary: APC2 c.1760A>G (p.Tyr587Cys) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 250340 control chromosomes (gnomAD). 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.1760A>G in individuals affected with APC2-Related Disorders and no experimental evidence demonstrating its impact on protein function have been reported. No submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.48
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.040
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.43	T;D;D;T
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D;.;D
M_CAP	Pathogenic	0.31	D
MetaRNN	Pathogenic	0.86	D;D;D;D
MetaSVM	Uncertain	-0.097	T
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-8.4	.;D;D;.
REVEL	Uncertain	0.49
Sift	Uncertain	0.0040	.;D;D;.
Sift4G	Uncertain	0.0020	D;D;D;D
Polyphen		1.0	.;D;D;.
Vest4		0.68, 0.69
MVP		0.65
MPC		1.6
ClinPred		1.0	D
GERP RS		4.6
Varity_R		0.70
gMVP		0.62

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: rs143029309; hg19: chr19-1462083;