chr1-205053254-A-G

Variant names:

• chr1-205053254-A-G
• NM_005076.5:c.69A>G

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_005076.5(CNTN2):​c.69A>G​(p.Ser23Ser) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: CNTN2 NM_005076.5 splice_region, synonymous
• Scores: Splicing: ADA: 0.2833
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.96

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_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.36).
• BP7: Synonymous conserved (PhyloP=1.96 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CNTN2	NM_005076.5	c.69A>G	p.Ser23Ser	splice_region_variant, synonymous_variant	Exon 2 of 23	ENST00000331830.7	NP_005067.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CNTN2	ENST00000331830.7	c.69A>G	p.Ser23Ser	splice_region_variant, synonymous_variant	Exon 2 of 23	1	NM_005076.5	ENSP00000330633.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Epilepsy, familial adult myoclonic, 5 Uncertain:1

Mar 26, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (gnomAD no frequency). This sequence change affects codon 23 of the CNTN2 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the CNTN2 protein. It affects a nucleotide within the consensus splice site. This variant has not been reported in the literature in individuals affected with CNTN2-related conditions. 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 is not likely to affect RNA splicing. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.36
CADD	Benign	15
DANN	Benign	0.83

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.28
dbscSNV1_RF	Benign	0.36
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-205022382;