rs1554490549

Positions:

• chr7-147485950-CTG-C

Variant summary

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

The NM_014141.6(CNTNAP2):​c.1689_1690del​(p.Cys563Ter) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,824 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CNTNAP2 NM_014141.6 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 9.89

Genes affected

CNTNAP2 (HGNC:13830): (contactin associated protein 2) This gene encodes a member of the neurexin family which functions in the vertebrate nervous system as cell adhesion molecules and receptors. This protein, like other neurexin proteins, contains epidermal growth factor repeats and laminin G domains. In addition, it includes an F5/8 type C domain, discoidin/neuropilin- and fibrinogen-like domains, thrombospondin N-terminal-like domains and a putative PDZ binding site. This protein is localized at the juxtaparanodes of myelinated axons, and mediates interactions between neurons and glia during nervous system development and is also involved in localization of potassium channels within differentiating axons. This gene encompasses almost 1.5% of chromosome 7 and is one of the largest genes in the human genome. It is directly bound and regulated by forkhead box protein P2, a transcription factor related to speech and language development. This gene has been implicated in multiple neurodevelopmental disorders, including Gilles de la Tourette syndrome, schizophrenia, epilepsy, autism, ADHD and intellectual disability. [provided by RefSeq, Jul 2017]

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 7-147485950-CTG-C is Pathogenic according to our data. Variant chr7-147485950-CTG-C is described in ClinVar as [Pathogenic]. Clinvar id is 468417.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CNTNAP2	NM_014141.6	c.1689_1690del	p.Cys563Ter	frameshift_variant	11/24	ENST00000361727.8
CNTNAP2	XM_017011950.3	c.1689_1690del	p.Cys563Ter	frameshift_variant	11/14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CNTNAP2	ENST00000361727.8	c.1689_1690del	p.Cys563Ter	frameshift_variant	11/24	1	NM_014141.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251480 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135918

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461824 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 727214

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cortical dysplasia-focal epilepsy syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Oct 05, 2022

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 468417). This variant has not been reported in the literature in individuals affected with CNTNAP2-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.003%). This sequence change creates a premature translational stop signal (p.Cys563*) in the CNTNAP2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CNTNAP2 are known to be pathogenic (PMID: 19896112, 21827697, 25045150, 26843181, 27439707). -

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 22, 2022

The c.1689_1690delTG (p.C563*) alteration, located in coding exon 11 of the CNTNAP2 gene, consists of a deletion of 2 nucleotides at position 1689 to 1690. This changes the amino acid from a cysteine (C) to a stop codon at amino acid position 563. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. Based on the available evidence, this alteration is classified as pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Apr 28, 2022

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1554490549; hg19: chr7-147183042;