rs121908568

Positions:

• chr17-65536495-G-A
• chr17-65536495-G-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_004655.4(AXIN2):​c.1966C>T​(p.Arg656*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: AXIN2 NM_004655.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 4.13

Genes affected

AXIN2 (HGNC:904): (axin 2) The Axin-related protein, Axin2, presumably plays an important role in the regulation of the stability of beta-catenin in the Wnt signaling pathway, like its rodent homologs, mouse conductin/rat axil. In mouse, conductin organizes a multiprotein complex of APC (adenomatous polyposis of the colon), beta-catenin, glycogen synthase kinase 3-beta, and conductin, which leads to the degradation of beta-catenin. Apparently, the deregulation of beta-catenin is an important event in the genesis of a number of malignancies. The AXIN2 gene has been mapped to 17q23-q24, a region that shows frequent loss of heterozygosity in breast cancer, neuroblastoma, and other tumors. Mutations in this gene have been associated with colorectal cancer with defective mismatch repair. [provided by RefSeq, Jul 2008]

AXIN2 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-65536495-G-A is Pathogenic according to our data. Variant chr17-65536495-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 5881.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-65536495-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
AXIN2	NM_004655.4	c.1966C>T	p.Arg656*	stop_gained	8/11	ENST00000307078.10	NP_004646.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AXIN2	ENST00000307078.10	c.1966C>T	p.Arg656*	stop_gained	8/11	1	NM_004655.4	ENSP00000302625.5
AXIN2	ENST00000375702.5	c.1771C>T	p.Arg591*	stop_gained	6/9	1		ENSP00000364854.5
AXIN2	ENST00000618960.4	c.1771C>T	p.Arg591*	stop_gained	7/10	5		ENSP00000478916.1
AXIN2	ENST00000578251.1	n.188C>T		non_coding_transcript_exon_variant	1/3	3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Oligodontia-cancer predisposition syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jul 13, 2022	This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Arg656*) in the AXIN2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in AXIN2 are known to be pathogenic (PMID: 15042511, 21416598). This premature translational stop signal has been observed in individual(s) with oligodontia and colorectal adenomatous polyps in a single family and has been also found in an independent individual with hypodontia (PMID: 15042511, 22581971). It has also been observed to segregate with disease in related individuals. For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 5881). -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	May 17, 2023	This variant is considered pathogenic. This variant creates a termination codon and is predicted to result in premature protein truncation. -
Pathogenic, no assertion criteria provided	literature only	OMIM	May 01, 2004	- -

not provided Pathogenic:2

Pathogenic, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 06, 2023

The p.R656* pathogenic mutation (also known as c.1966C>T), located in coding exon 7 of the AXIN2 gene, results from a C to T substitution at nucleotide position 1966. This changes the amino acid from an arginine to a stop codon within coding exon 7. This alteration was found to segregate with disease within a Finnish family presenting with oligodontia and colorectal cancer (Lammi L et al. Am J Hum Genet, 2004 May;74:1043-50). This alteration was also identified in 1 of 1923 Chinese patients with a personal history of colorectal cancer (Yao J et al. Cancer Biol Med, 2022 Jan;19:707-32). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	47
DANN	Uncertain	1.0
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Uncertain	0.92	D
Vest4		0.92
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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: rs121908568; hg19: chr17-63532613; COSMIC: COSV61057242; COSMIC: COSV61057242;