1-228157820-C-T

Position:

• chr1-228157820-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_020435.4(GJC2):​c.62C>T​(p.Thr21Ile) variant causes a missense change involving the alteration of a 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 Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GJC2 NM_020435.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.64

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GJC2	NM_020435.4	c.62C>T	p.Thr21Ile	missense_variant	2/2	ENST00000366714.3	NP_065168.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GJC2	ENST00000366714.3	c.62C>T	p.Thr21Ile	missense_variant	2/2	1	NM_020435.4	ENSP00000355675.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 38

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypomyelinating leukodystrophy 2 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Molecular Diagnostics Lab, Nemours Children's Health, Delaware	May 24, 2021	This missense variant (c.62C>T, p.Thr21Ile) has not been observed in population databases (gnomAD) and has not been reported in the literature. Variant prediction programs suggest a deleterious effect, but no functional studies have been reported. The change was found in the homozygous state in affected twins. -
Uncertain significance, criteria provided, single submitter	clinical testing	Consultorio y Laboratorio de Neurogenética, Hospital JM Ramos Mejia	-	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Uncertain	0.68
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.91	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.2	H
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-5.5	D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.99	D
Vest4		0.95
MutPred		0.91		Loss of catalytic residue at T21 (P = 0.0247);
MVP		0.97
ClinPred		1.0	D
GERP RS		4.2
Varity_R		0.84
gMVP		0.98

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: rs2034705112; hg19: chr1-228345521;