12-40910072-GA-G

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1_Strong PM2 PP3_Moderate PP5_Moderate

The NM_001843.4(CNTN1):c.62del(p.Glu21GlyfsTer59) variant causes a frameshift, splice region change. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CNTN1 NM_001843.4 frameshift, splice_region
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.92

Genes affected

CNTN1 (HGNC:2171): (contactin 1) The protein encoded by this gene is a member of the immunoglobulin superfamily. It is a glycosylphosphatidylinositol (GPI)-anchored neuronal membrane protein that functions as a cell adhesion molecule. It may play a role in the formation of axon connections in the developing nervous system. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2011]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 10 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 12-40910072-GA-G is Pathogenic according to our data. Variant chr12-40910072-GA-G is described in ClinVar as [Pathogenic]. Clinvar id is 1432053.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CNTN1	NM_001843.4	c.62del	p.Glu21GlyfsTer59	frameshift_variant, splice_region_variant	3/24	ENST00000551295.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CNTN1	ENST00000551295.7	c.62del	p.Glu21GlyfsTer59	frameshift_variant, splice_region_variant	3/24	1	NM_001843.4	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Compton-North congenital myopathy Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Apr 04, 2021

This variant is not present in population databases (ExAC no frequency). For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has not been reported in the literature in individuals with CNTN1-related conditions. This sequence change creates a premature translational stop signal (p.Glu21Glyfs*59) in the CNTN1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CNTN1 are known to be pathogenic (PMID: 19026398, 22242131). -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.99		Position offset: 2
DS_AL_spliceai		0.96		Position offset: 1

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: chr12-41303874;