1-205070463-G-C

Variant names:

• chr1-205070463-G-C
• rs138090348
• NM_005076.5:c.2469G>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_005076.5(CNTN2):​c.2469G>C​(p.Gly823Gly) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,726 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. G823G) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CNTN2 NM_005076.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -1.25
• Publications: 0 publications found

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]

CNTN2 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• epilepsy, familial adult myoclonic, 5

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• benign adult familial myoclonic epilepsy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.78).
• BP7: Synonymous conserved (PhyloP=-1.25 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CNTN2	NM_005076.5	c.2469G>C	p.Gly823Gly	synonymous_variant	Exon 19 of 23	ENST00000331830.7	NP_005067.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CNTN2	ENST00000331830.7	c.2469G>C	p.Gly823Gly	synonymous_variant	Exon 19 of 23	1	NM_005076.5	ENSP00000330633.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461726 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727160

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86240

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53346

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111954

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.78
CADD	Benign	6.1
DANN	Benign	0.62
PhyloP100		-1.2
Mutation Taster		=100/0	polymorphism

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

Other links and lift over

dbSNP: rs138090348; hg19: chr1-205039591;