1-205067157-T-A

Position:

• chr1-205067157-T-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Strong

The NM_005076.5(CNTN2):​c.2032T>A​(p.Trp678Arg) variant causes a missense 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. 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. W678G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CNTN2 NM_005076.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.02

Genes affected

CNTN2 (HGNC:2172): (contactin 2) This gene encodes a member of the contactin family of proteins, part of the immunoglobulin superfamily of cell adhesion molecules. The encoded glycosylphosphatidylinositol (GPI)-anchored neuronal membrane protein plays a role in the proliferation, migration, and axon guidance of neurons of the developing cerebellum. A mutation in this gene may be associated with adult myoclonic epilepsy. [provided by RefSeq, Sep 2016]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), CNTN2. . Gene score misZ 2.5878 (greater than the threshold 3.09). Trascript score misZ 3.2882 (greater than threshold 3.09). GenCC has associacion of gene with benign adult familial myoclonic epilepsy, complex neurodevelopmental disorder, epilepsy, familial adult myoclonic, 5.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.952

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CNTN2	NM_005076.5	c.2032T>A	p.Trp678Arg	missense_variant	16/23	ENST00000331830.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CNTN2	ENST00000331830.7	c.2032T>A	p.Trp678Arg	missense_variant	16/23	1	NM_005076.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Epilepsy, familial adult myoclonic, 5 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 31, 2022

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 sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 474473). This variant has not been reported in the literature in individuals affected with CNTN2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces tryptophan, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 678 of the CNTN2 protein (p.Trp678Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Benign	0.39	T;T;.
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	.;.;D
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.95	D;D;D
MetaSVM	Uncertain	-0.14	T
MutationAssessor	Uncertain	2.6	M;M;.
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-13	.;D;.
REVEL	Pathogenic	0.72
Sift	Pathogenic	0.0	.;D;.
Sift4G	Pathogenic	0.0	.;D;.
Polyphen		1.0	D;D;.
Vest4		0.91
MutPred		0.77		Gain of sheet (P = 0.1539);Gain of sheet (P = 0.1539);Gain of sheet (P = 0.1539);
MVP		0.92
MPC		1.7
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.91
gMVP		0.67

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: rs1553347245; hg19: chr1-205036285;