chr1-205058071-G-C

Variant names:

• chr1-205058071-G-C
• rs370377460
• NM_005076.5:c.215+6G>C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_005076.5(CNTN2):​c.215+6G>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000139 in 1,612,916 control chromosomes in the GnomAD database, including 1 homozygotes. 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: 𝑓 0.00013 (1 hom., cov: 32)
  • Exomes 𝑓: 0.00014 (0 hom.)
• Consequence: CNTN2 NM_005076.5 splice_region, intron
• Scores: Splicing: ADA: 0.00008703
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 B:1
• Conservation: PhyloP100: -0.262

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 -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.7).
• BS1: Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.000131 (20/152256) while in subpopulation NFE AF= 0.000191 (13/68040). AF 95% confidence interval is 0.000112. There are 1 homozygotes in gnomad4. There are 7 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CNTN2	NM_005076.5	c.215+6G>C		splice_region_variant, intron_variant	Intron 3 of 22	ENST00000331830.7	NP_005067.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CNTN2	ENST00000331830.7	c.215+6G>C		splice_region_variant, intron_variant	Intron 3 of 22	1	NM_005076.5	ENSP00000330633.4

Frequencies

GnomAD3 genomes AF: 0.000131 AC: 20 AN: 152256 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.000169

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000191

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000570 AC: 14 AN: 245448 Hom.: 0 AF XY: 0.0000675 AC XY: 9 AN XY: 133424

Gnomad AFR exome AF: 0.0000649

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: 0.000118

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000140 AC: 204 AN: 1460660 Hom.: 0 Cov.: 32 AF XY: 0.000145 AC XY: 105 AN XY: 726626

Gnomad4 AFR exome AF: 0.0000896

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: 0.000166

Gnomad4 OTH exome AF: 0.000265

GnomAD4 genome AF: 0.000131 AC: 20 AN: 152256 Hom.: 1 Cov.: 32 AF XY: 0.0000941 AC XY: 7 AN XY: 74392

Gnomad4 AFR AF: 0.000169

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000191

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000113 Hom.: 0

Bravo AF: 0.0000982

EpiCase AF: 0.000218

EpiControl AF: 0.0000595

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Epilepsy, familial adult myoclonic, 5 Uncertain:1

Aug 23, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 3 of the CNTN2 gene. It does not directly change the encoded amino acid sequence of the CNTN2 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs370377460, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with CNTN2-related conditions. ClinVar contains an entry for this variant (Variation ID: 541410). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. 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. -

CNTN2-related disorder Benign:1

Mar 08, 2019

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.70
CADD	Benign	3.3
DANN	Benign	0.72

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000087
dbscSNV1_RF	Benign	0.0020
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: rs370377460; hg19: chr1-205027199;