rs1553262438

Positions:

• chr1-228157899-C-G

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_020435.4(GJC2):​c.141C>G​(p.Tyr47*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GJC2 NM_020435.4 stop_gained
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.69

Genes affected

GJC2 (HGNC:17494): (gap junction protein gamma 2) This gene encodes a gap junction protein. Gap junction proteins are members of a large family of homologous connexins and comprise 4 transmembrane, 2 extracellular, and 3 cytoplasmic domains. This gene plays a key role in central myelination and is involved in peripheral myelination in humans. Defects in this gene are the cause of autosomal recessive Pelizaeus-Merzbacher-like disease-1. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 52 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-228157899-C-G is Pathogenic according to our data. Variant chr1-228157899-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 527995.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GJC2	NM_020435.4	c.141C>G	p.Tyr47*	stop_gained	2/2	ENST00000366714.3	NP_065168.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GJC2	ENST00000366714.3	c.141C>G	p.Tyr47*	stop_gained	2/2	1	NM_020435.4	ENSP00000355675.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 37

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Spastic paraplegia Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 02, 2017

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Different truncation variants that lie downstream of this variant have been reported in individuals affected with Pelizaeus-Merzbacher-like disease (PMID: 18094336, 20513814). This suggests that deletion of this region of the GJC2 protein is causative of disease. This variant has not been reported in the literature in individuals with GJC2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change results in a premature translational stop signal in the GJC2 gene (p.Tyr47*). While this is not anticipated to result in nonsense mediated decay, it is expected to delete the last 393 amino acids of the GJC2 protein. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	36
DANN	Uncertain	1.0
Eigen	Uncertain	0.39
Eigen_PC	Benign	0.18
FATHMM_MKL	Uncertain	0.88	D
Vest4		0.68
GERP RS		2.2

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: rs1553262438; hg19: chr1-228345600;