rs1554440667

Positions:

• chr7-147121001-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_014141.6(CNTNAP2):​c.777A>G​(p.Ile259Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,474 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CNTNAP2 NM_014141.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.318

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]

CNTNAP2 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CNTNAP2	NM_014141.6	c.777A>G	p.Ile259Met	missense_variant	6/24	ENST00000361727.8	NP_054860.1
CNTNAP2	XM_017011950.3	c.777A>G	p.Ile259Met	missense_variant	6/14		XP_016867439.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CNTNAP2	ENST00000361727.8	c.777A>G	p.Ile259Met	missense_variant	6/24	1	NM_014141.6	ENSP00000354778.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461474 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727034

Gnomad4 AFR exome AF: 0.00

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cortical dysplasia-focal epilepsy syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 26, 2021

This sequence change replaces isoleucine with methionine at codon 259 of the CNTNAP2 protein (p.Ile259Met). The isoleucine residue is moderately conserved and there is a small physicochemical difference between isoleucine and methionine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with CNTNAP2-related conditions. 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: "Possibly Damaging"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.060
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Benign	0.30	T;T
Eigen	Benign	0.14
Eigen_PC	Benign	0.071
FATHMM_MKL	Benign	0.62	D
LIST_S2	Uncertain	0.93	.;D
M_CAP	Benign	0.035	D
MetaRNN	Uncertain	0.61	D;D
MetaSVM	Benign	-0.34	T
MutationAssessor	Uncertain	2.3	M;M
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-0.26	N;.
REVEL	Uncertain	0.43
Sift	Benign	0.040	D;.
Sift4G	Benign	0.10	T;.
Polyphen		0.96	D;D
Vest4		0.78
MutPred		0.50		Gain of disorder (P = 0.0474);Gain of disorder (P = 0.0474);
MVP		0.82
MPC		0.40
ClinPred		0.93	D
GERP RS		-0.69
Varity_R		0.11
gMVP		0.32

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: rs1554440667; hg19: chr7-146818093;